Eighty-seven (87, LXXXVII) is the natural number following eighty-six and preceeding eighty-eight. It is the sum of the squares of the first four primes.
- Hexadecimal: 57
- Binary: 01010111
- Factors: 1, 3, 29, 87.
- Factorization:
- Ordinal number: eighty-seventh
- 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.