The Quite Incredible Number List: 6801-6900

6801: 6801 is 1089 upside-down, which suggests a new twist on an old trick. Ask a friend to do the following:

(1) Write down any three-digit number whose first and last digits differ by two or more.

(2) Reverse the number, and subtract the smaller number from the larger.

(3) Take the result, reverse it, and add it to the previous result.

(4) Write the answer on a piece of paper and seal it in an envelope.

You then think very hard and announce "Was your answer 6801?" They say no. Puzzled, you ask them to give you the envelope. You take out the sheet of paper, hold it upside-down and say "Well that's what it says here!" (Brock)

6802: European Union customs tariff (TARIC) codes beginning with 6802 apply to worked monumental or building stone. (Big Martin)

6803: Fires in the Amazon rainforest went up by 28% to 6803 in July 2020, compared with the previous year. (Brock)

6804: According to the 1821 book The Universal Cambist the principal measure of cloth in Egypt was the Pic, which measured 0.6804 metres. (Big Martin)

6805: Foyle Foodbank in County Derry provided food to 6805 people in 2020. (Brock)

6806: The Avenue Country Park in Derbyshire is at grid reference SK3887 6806. (Big Martin)

6807: At the 2017 general election, Labour's Luke Pollard gained the marginal seat of Plymouth Sutton and Devonport from the Conservatives with a majority of 6807. His majority was originally declared as 6002, but was revised after the council admitted an error in not counting 6599 votes from the Efford and Lipson ward. The Plymouth Labour leader described the situation as an "omnishambles". (Brock)

6808: Brianne Theisen-Eaton holds the Canadian record for the heptathlon with 6,808 points. (Big Martin)

6809: The Motorola 6809 micro processor is an enhanced version of the 6800 micro processor. (Awitt)

6810: The Yamaha YTR-6810 is a piccolo trumpet. (Big Martin)

6811: 6811 and 6812 are a Ruth-Aaron pair of the first type. (See here for the definition and an explanation of the name.)

6811 = 72 x 139, and 7 + 139 = 146

6812 = 22 x 13 x 131, and 2 + 13 + 131 = 146

(Brock)

6812: 6812 is the code number for Lufthansa flight tracker. (Awitt)

6813: An estimated 8% of scientists who participated in an anonymous survey of research practices at Dutch universities confessed to falsifying and/or fabricating data at least once between 2017 and 2020. Between October and December 2020, study authors contacted nearly 64,000 researchers at 22 universities in the Netherlands, 6813 of whom completed the survey. More than half (51%) of respondents to the Dutch survey also reported frequently engaging in at least one of 11 "questionable research practices". (Brock)

6814: Executive Order 6814 was issued by Franklin Delano Roosevelt under the Silver Purchase Act of 1934. (Big Martin)

6815: The population of Horncastle in Lincolnshire at the 2011 census was 6815. (Brock)

6816: Dutch postcode 6816 covers an area just to the north of central Arnhem. (Big Martin)

6817: 6817 = 2⁸ + 3⁸. (Brock)

6818: In 2015, 6,818 people across south-west England took part in Dryathlon and raised £451,383 for cancer research. (Big Martin)

6819: HR 6819, also known as HD 167128 or QV Telescopii, is a double or triple star system in the southern constellation of Telescopium. A May 2020 study hypothesized that the system has the closest known black hole, and the first one in a system visible to the naked eye, although three later papers argued that it consists of two mainstream stars and no black hole at all. (Brock)

6820: The Drager Alcotest 6820 is a make of breathalyser. (Big Martin)

6821: 6821 is the code for the Lego shovel buggy. (Awitt)

6822: In 2005, a Ukrainian team set a world depth record by reaching 6,822 feet below ground in a cave in Georgia. (Big Martin)

6823: The three large groups of European airlines - International Consolidated Airlines Group (IAG), Air France-KLM and Lufthansa - lost 6823 million euros between them in the first half of 2021. (Brock)

6824: GWR Dean Tricomposite, 6-wheel, broad gauge coach 6824 was built in 1887 and constructed in such a way as to be easily converted to standard gauge. Only the body survives and it is currently being reconstructed at Didcot Railway Centre. (Big Martin)

6825: There are 6825 ways of placing 10 labelled balls into 3 indistinguishable boxes with at least 2 balls in each box. (Brock)

6826: The SkyJack 6826 is a make of diesel scissor lift. (Big Martin)

6827: After acquiring the maintenance contracts for 10 road tunnels in London in 2021, Kier Highways now has responsibility for 15 tunnels nationwide, with a combined bore length of 6827 km. (Brock)

6828: A Bermuda vs Guernsey online comparison reveals that 6,828 people are employed in the financial sector in Guernsey. (Big Martin)

6829: This green GPO bakelite pyramid telephone (model 6829) is available from a company called "Telephone Lines" for £850. (Brock)

6830: The Digital Index Of Middle English Verse entry DIMEV6830 is A Tretise For Lauandres attributed to John Lydgate. (Big Martin)

6831: Denise Lewis's personal best score for the heptathlon is 6831 points, set at the Décastar meeting in 2000. (Brock)

6832: HMS Ocean of 1863 was being built as a 91-gun ship of the line but completed as an armoured frigate to increase the Royal Navy's roster of ironclads. She displaced 6,832 long tons. (Big Martin)

6833: Aeroflot Flight 6833, en route from Tbilisi to Leningrad (as it was then), was the scene of an attempted aircraft hijacking by seven young Georgians on 18-19 November 1983. (Brock)

6834: Nordhavn yacht 6834 was delivered to its owner in Port Everglades, Florida last year. (Big Martin)

6835: A tub of 75 Kimberly-Clark antibacterial wipes has the code number 6835. (Awitt)

6836: Former BR locomotive D6836 is now preserved on the Watercress Line in Hampshire. (Big Martin)

6837: There are 6837 perfect squares with eight digits. The lowest is 10,004,569 (equal to 3163²) and the highest is 99,980,001 (equal to 9999²). (Brock)

6838: The American Air Museum in Britain has a photograph Flying Fortress bomber 44-6838 Spirit of Martinez with the crew. (Big Martin)

6839: Archaeologists recently stumbled across a lava tube cavern in northwestern Saudi Arabia that is packed with hundreds of thousands of bones gathered by striped hyenas. Radiocarbon dating of the samples suggests the animal remains range from 439 to 6839 years ago. (Brock)

6840: Historic Environment Scotland's listed building LB6840 is Spean Bridge, constructed by Thomas Telford in 1819. (Big Martin)

6841: This ring costs (Aus) $6841. (Awitt)

6842: Here are some photos of NXWM bus 6842 around the West Midlands area over recent years. (Big Martin)

6843: Plagodis fervidaria is a species of geometrid moth found in North America. Its MONA or Hodges number is 6843. (Brock)

6844: The Makita 6844 is an auto-feed screwdriver. (Big Martin)

6845: The Motorola 6845 was a display controller that was widely used in 8-bit computers during the 1980s. (Brock)

6846: In 2001, 6,846 young people from 159 schools sang at Manchester Evening News Arena, setting a Guinness World Record. (Big Martin)

6847: The total expenditure of St Edmundsbury and Ipswich Diocesan Cursillo in the year to 31 December 2019 was £6847. (Brock)

6848: In 2017, the Guardian carried on article on "the £6,848 question for postgraduate students". (Big Martin)

6849: In advance of Barack Obama's first inauguration in January 2009, the Washington (DC) radio station WTOP was reporting that there would be only one toilet for every 6849 people. (Brock)

6850: Here is some YouTube footage of a 3-gauge live-steam model of GWR loco 6850, Cleve Grange (Big Martin)

6851: On 9 February 1989 there were 6851 unemployed claimants in the Glasgow, Springburn parliamentary constituency. (Ed.)

6852: 6852 is the code for this wallpaper. (Awitt)

6853: NGC 6853 is the amusingly named Dumbbell Nebula, in the constellation Vulpecula, about 1360 light-years away. It was the first planetary nebula to be discovered, by Charles Messier in 1764. (Brock)

6854: Nautgardsoksli is a 6854-foot-high mountain in Jotunheimen National Park, Norway. (Ed.)

6855: Café 6855 can be found at 6855 4th St NW, Los Ranchos, New Mexico. Specialities include Breakfast Steak and Eggs, Breakfast Enchiladas, Belgian Waffles with Berries, and the North 4th Egg Sandwich. (Brock)

6856: 6856 is the product code for this pair of trees. (Awitt)

6857: Rionegro, a city and municipality in the Antioquia Department of Colombia, stands at an elevation of 6857 feet (2090 metres). (Brock)

6858: 6858 is in the URL for a 2020 Financial Times article by Yuval Noah Harari entitled "The world after coronavirus". (Awitt)

6859: 6859 is a perfect cube (= 19³). (Brock)

6860: Lego set 6860 is the Batcave. (Big Martin)

6861: A combination of seasonal vaccination and chemoprevention reduced malaria episodes and deaths among children by around 70% compared with either intervention alone during a 3-year study in two African countries, it was reported in 2021. The study was carried out among 6861 children aged 5 to 17 months in Burkina Faso and Mali. (Brock)

6862: Canadian Pacific locomotive 6862 was built in Montreal in 1958 and is a booster unit without a cab. It is now at the Monticello Railway Museum. (Big Martin)

6863: 6863 is the item code for a washroom dispenser. (Awitt)

6864: The retreat featured on the American miniseries Nine Perfect Strangers, in reality the Soma Luxury Estate in Byron Bay, New South Wales, can be rented out by guests for $6864 (Australian) per night, with a minimum four-night stay. (Brock)

6865: TEAM Linhas Aereas Flight 6865 hit the top of Pico da Pedra Bonita in Brazil on March 31 2006, killing everyone on board. (Big Martin)

6866: According to The Free Dictionary, 6866 is a New Zealand police radio code meaning "uses firearm to prevent or resist arrest". (Brock)

6867: Shirehampton (or "Shire" as it's known locally) has a population of 6,867. (Big Martin)

6868: The former Indian cricket captain Dilip Vengsarkar scored a total of 6868 Test runs. (Brock)

6869: 6869 is the transcript number for a media release of former Aus PM Bob Hawke in 1986. (Awitt)

6870: The Brimar 6870 electrical valve was first produced in the 1950s. (Big Martin)

6871: On Prime Curios, Gaydos asks: "Is 6871 the only prime number for which its cube (324384314311) and the cube of its reverse (1786³=5696975656) have no digits in common?" I don't know, but there can't be too many of them! (Brock)

6872: Kebnekaise, Sweden's highest mountain, is now 6,872 feet high - having shrunk by nearly 6.5 feet since 2020 due to melting of its icy peak from global warming. (Big Martin)

6873: Cryptocurrencies and "non-fungible tokens" are a closed book to me, as I think I've mentioned before, so I report with some bafflement that there are a number of non-fungible penguins on the internet - to be precise, 8888 artworks known as "Pudgy Penguins". The most expensive appears to be Pudgy Penguin #6873, valued at around $469,000 if I've understood correctly. No I can't believe it either. (Brock)

6874: According to an article by Hilton Car Supermarket the average yearly mileage for male drivers is 6,874 miles, with female drivers not far behind at 6,807 miles. (Big Martin)

6875: 6875 can be expressed using five 5's: 5 x 5 x 5 x 55. (Brock)

6876: 6876 is an outdoor clothing brand. (Big Martin)

6877: 6877 is the product code for a fanless embedded computer. (Awitt)

6878: Sandoy in the Faroe Islands has a population of only around 1,200, but supports 6,878 adult sheep and their lambs. (Big Martin)

6879: Scotland's National Walking and Cycling Network - which includes Scotland's Great Trails, the National Cycle Network and Scottish Canals towpaths - stretches for 6879 kilometres across the country. (Brock)

6880: The Betton Grange Society is building locomotive 6880. The GWR built 80 "Grange" class engines, numbered from 6800 to 6879, but none have survived, so an 81st "Grange" is being built. (Big Martin)

6881: 273 Turkish citizens were evacuated from Afghanistan after the Taliban took control of Kabul. They were first taken to Islamabad by a transport plane belonging to the Turkish Air Force, and then to Istanbul Airport via a Turkish Airlines flight numbered TK 6881. (Brock)

6882: 6882 is the code number for the instructions of this Lego character. (Awitt)

6883: 6883 diverse apple varieties are maintained at the Plant Genetic Resources Unit run by the US Department of Agriculture at Geneva, Ontario County, New York State. (Brock)

6884: 6884 (aka Stefano Ugliano) is a musical artist. (Big Martin)

6885: The home full programme fee for many of The University of Chester's taught MA courses for 2022/23 is £6885. (Brock)

6886: The Forces War Records for the Royal Marine Light Infantry cover 6,886 people for the Boer War alone. (Big Martin)

6887: As at September 2021, there were 6887 foreign workers from 101 countries working in Fiji. (Brock)

6888: The 6888th Central Postal Directory Battalion was an all-black unit of the U.S. Women's Army Corps operational in late WW2 and just after. (Big Martin)

6889: 6889 is not only a perfect square (83²), it's also strobogrammatic (the same upside-down). It's the first such number greater than 1, and only two higher numbers of this type are known: 69169 and 109181601. A rarity indeed! (Brock)

6890: The Agilent HP 6890 is a gas chromatograph. (Big Martin)

6891: Between 1850 and 1860, the length of the German railway grew from 3639 to 6891 miles. (Brock)

6892: 6892 is the product code for this air freshener. (Awitt)

6893: 6893 traffic jams were recorded on motorways in the German state of Hesse between 16 July and 29 August 2021. (Article in German.) (Brock)

6894: Elton John's 1980 album Goodbye Yellow Brick Road was released by MCA Records as MCA2-6894. (Big Martin)

6895: 6895 is the product code for this Stella York dress. (Awitt)

6896: The UK exported 6896 tonnes of plastic waste to south-east Asia in September 2020. Most of the destinations are considered to be substandard waste management facilities. This practice would have been forbidden if the UK had remained in the EU. (Brock)

6897: The Kotlar Collection J-6897 is some diamond studs. (Big Martin)

6898: As a result of the recent flooding in the Indian state of Assam, a total of 6898 people have taken shelter in 62 relief camps set up by the district administrations of Bongaigaon, Chirang, Dhemaji and Majuli (report dated August 29). (Brock)

6899: British Museum item Am.6899 is a wooden club from South America. (Big Martin)

6900: The Claas Lexion 6900 is a combine harvester and not, as you might expect, a sex toy. (Celebaelin)