Eighty

Eighty (80, LXXX) is the natural number following seventy-nine and preceeding eighty-one.

• Hexadecimal: 50
• Binary: 01010000
• Greek numeral: π´
• Factors: 1, 2, 4, 5, 8, 10, 16, 20, 40, 80
• Factorization:
• Ordinal number: eightieth
• Numeral system base 80: octagesimal
• Name in other languages: quatre-vingt (in French, from four and twenty), see also wiktionary:eighty

See also: seventy, eighty, ninety, integer, list of numbers.

80 is also:

• the atomic number of mercury (Hg)
• the number of units in a fourscore
• the age at which one becomes an octogenarian
• in the title of Around the World in Eighty Days by Jules Verne
• the model number of the computers TRS-80, IBM 80, Sinclair ZX80, Aster CT-80
• the model number of T-80, a Soviet tank; IAR 80, a Romanian WWII fighter aircraft; McDonnell Douglas MD-80, Arado Ar 80, F-80 Shooting Star
• part of the name of the bands Eighty-D and Eighty Proof Soul
• the age limit for cardinals to vote at papal conclaves
• the percentage of work done with 20% of the resources according to a "80/20 rule"
• the length of a beach in Western Australia: Eighty Mile Beach
• the length of the Eighty Years' War or Dutch revolt (1568-1648)
• the number of the French department Somme
• the designation of Interstate 80, a freeway that runs from California to New Jersey; the European route E80 from Lisbon to Gürbulak
• the standard TCP/IP port number for HTTP connection
• the year AD 80 or AD 1980.

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Eighty-one (81, LXXXI) is the natural number following eighty and preceeding eighty-two.

• Hexadecimal: 51
• Binary: 01010001
• Factors: 1, 3, 9, 27, 81
• Factorization:
• Ordinal number: eighty-first

81 is also:

• the atomic number of thallium (Tl)
• the title of a short film by Stephen Burke: 81
• the model number of: Unterseeboot 81, Sinclair ZX81
• the Messier number of the M81 Group of galaxies
• the number of the French department Tarn
• the designation of Interstate 81, a freeway that runs from Tennessee to New York.
• the code for international direct dial phone calls to Japan
• the year AD 81 or AD 1981.

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Eighty-two (82, LXXXII) is the natural number following eighty-one and preceeding eighty-three.

• Hexadecimal: 52
• Binary: 01010010
• Factors: 1, 2, 41, 82
• Factorization:
• Ordinal number: eighty-second

82 is also:

• the atomic number of lead (Pb)
• the model number of: Mark 82 bomb, a nonguided general purpose bomb
• the Messier number of the M82 galaxy
• the number of the French department Tarn-et-Garonne
• the code for international direct dial phone calls to South Korea
• the year AD 82 or AD 1982.

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Eighty-three (83, LXXXIII) is the natural number following eighty-two and preceeding eighty-four. It is the sum of three consecutive primes (23 + 29 + 31) as well as the sum of five consecutive primes (11 + 13 + 17 + 19 + 23).

• Hexadecimal: 53
• Binary: 01010011
• Factors: 1, 83
• the 23rd prime number, following seventy-nine and preceeding eighty-nine
• Ordinal number: eighty-third

83 is also:

• the atomic number of bismuth (Bi)
• the hours in 83 Hours 'Til Dawn
• the model number of Bell XP-83
• the Messier number of M83, the Southern Pinwheel Galaxy
• the number of the French department Var
• the designation of Interstate 83, a freeway that runs from Maryland to Pennsylvania; European route E83 from Bjala to Sofia
• the year AD 83 or AD 1983.

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Eighty-four (84, LXXXIV) is the natural number following eighty-three and preceeding eighty-five. It's the sum of the first seven triangular numbers, as well as the sum of a twin prime (41 + 43).

• Hexadecimal: 54
• Binary: 01010100
• Factors: 1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 84.
• Factorization:
• Ordinal number: eighty-fourth

84 is also

• the atomic number of polonium (Po)
• the model number of AGM-84 Harpoon
• WGS 84
• the house number of 84 Avenue Foch
• the number of the French department Vaucluse
• the designation of Interstate 84, a freeway that runs from Oregon to Utah and from Pennsylvania to Massachusetts.
• the code for international direct dial phone calls to Vietnam
• a town in Pennsylvania: Eighty Four
• the year AD 84 or AD 1984.

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Eighty-five (85, LXXXV) is the natural number following eighty-four and preceeding eighty-six.

• Hexadecimal: 55
• Binary: 01010101
• Factors: 1, 5, 17, 85.
• Factorization:
• Ordinal number: eighty-fifth

85 is also:

• the atomic number of astatine (At)
• the model number of SU-85
• the number of the French department Vendée
• the designation of Interstate 85, a freeway that runs from Alabama to Virginia; the European route E85 from Klaipéda to Alexandropoúli
• the year AD 85 or AD 1985.

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Eighty-six (86, LXXXVI) is the natural number following eighty-five and preceeding eighty-seven.

• Hexadecimal: 56
• Binary: 01010110
• Factors: 1, 2, 43, 86.
• Factorization:
• Ordinal number: eighty-sixth

86 is also:

• the atomic number of radon (Rn)
• the model number of: F-86 Sabre, Ilyushin Il-86
• the model number of CPM-86,
• part of the model number of the X86 microprocessors
• used as a verb, to "eighty-six" means to "ignore" or "get rid of". This may originally be Cockney rhyming slang for the word "nix".
• In the TV series Get Smart, the principal character Maxwell Smart was known as Agent 86.
• the name of the band The Eighty-Six
• the number of the French department Vienne
• the designation of Interstate 86, a freeway in Idaho.
• the code for international direct dial phone calls to China
• the year AD 86 or AD 1986.

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Eighty-seven (87, LXXXVII) is the natural number following eighty-six and preceeding eighty-eight.

• Hexadecimal: 57
• Binary: 01010111
• Factors: 1, 3, 29, 87.
• Factorization:
• Ordinal number: eighty-seventh

87 is also:

• the atomic number of francium (Fr)
• the number of years between the signing of the U.S. Declaration of Independence and the Battle of Gettysburg, immortalized in Abraham Lincoln's Gettysburg Address: Fourscore and seven years ago, our forefathers...
• the model number of Junkers Ju 87
• the Messier number of M87, a giant elliptical galaxy.
• the number of the French department Haute-Vienne
• the designation of Interstate 87, a freeway in New York; the European route E87 from Tulcea to Antalya
• the code for international direct dial phone calls to Inmarsat and other services
• the year AD 87 or AD 1987.

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Eighty-eight (88, LXXXVIII) is the natural number following eighty-seven and preceeding eighty-nine. It's a symmetrical or palindromic number.

• Hexadecimal: 58
• Binary: 01011000
• Factors: 1, 2, 4, 8, 11, 22, 44, 88.
• Factorization:
• Ordinal number: eighty-eighth

88 is also:

• the atomic number of radium (Ra)
• the number of keys on a piano
• in the title of the song Rocket 88
• the model number of Oldsmobile Eighty-Eight, AGM-88 HARM
• the caliber of the World War II anti-aircraft gun 88mm FLAK
• used in neo-nazi circles as a code word for Heil Hitler, H being the 8th letter in the alphabet.
• the number of the French department Vosges
• the designation of Interstate 88, a freeway in Illinois
• a town in Kentucky: Eighty Eight
• the year AD 88 or AD 1988.

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Eighty-nine (89, LXXXIX) is the natural number following eighty-eight and preceeding ninety.

• Hexadecimal: 59
• Binary: 01011001
• Factors: 1, 89.
• the 24th prime number, following eighty-three and preceeding ninety-seven, a Fibonacci number
• Ordinal number: eighty-ninth

89 is also:

• the atomic number of actinium (Ac)
• the model number of CBU-89 Gator, TI-89
• part of the name of the baseball team Oklahoma City 89ers (1962-1997)
• the number of the French department Yonne
• the designation of Interstate 89, a freeway that runs from New Hampshire to Vermont
• the year AD 89, 1889, or 1989.