87 (number)
From Wikipedia, the free encyclopedia
87 (eighty-seven) is the natural number following 86 and preceding 88.
Cardinal | 87 eighty-seven |
Ordinal | 87th eighty-seventh |
Factorization | |
Divisors | 1, 3, 29, 87 |
Roman numeral | LXXXVII |
Binary | 01010111 |
Hexadecimal | 57 |
[edit] In mathematics
Eighty-seven is the sum of the squares of the first four primes. It is also the sum of the sum of divisors of the first ten integers.
[edit] In astronomy
- Messier object M87, a magnitude 11.0 elliptical galaxy in the constellation Virgo, also known as the Virgo A Galaxy
- The New General Catalogue object NGC 87, a galaxy in the constellation Phoenix, a member of Robert's Quartet
- The Saros number of the solar eclipse series which began on 77 BC February 3 and ended on 1222 April 13. The duration of Saros series 87 was 1298.1 years, and it contained 73 solar eclipses. Further, the Saros number of the lunar eclipse series which began on 9 July 25 and ended on 1325 September 23. The duration of Saros series 87 was 1316.2 years, and it contained 74 lunar eclipses.
[edit] In other fields
Eighty-seven is also:
- The atomic number of francium
- Considered an unlucky score (the devil's number) in cricket in Australia, thought to originate from the fact that 87 is 13 runs short of a century, equivalent a Nelson's, Double-Nelson's etc (111, 222 etc) in English cricket.
- 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 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 87 photographic filter blocks visible light]] allowing only infrared light to pass
- A slang term for anilingus
- The ISBN Group Identifier for books published in Denmark.
- The year AD 87, 87 BC, or 1987.
- 87 is the exact number of people who died in the Waco Branch Davidian fire.
- the opus number of the 24 Preludes and Fugues of Dmitri Shostakovich.
- The uniform numbers of hockey superstar Sidney Crosby and Denver Broncos wide receiver Ed McCaffrey.
- In model railroading, the ratio of the popular HO scale is 1:87.