1987 (number)

1987 is the natural number following 1986 and preceding 1988.

In mathematics

1987 is an odd number and the 300th prime number. It starts the sexy prime triplet (1987, 1993, 1999). Being of the form 4n + 3, it is a Gaussian prime. It is a lucky number and therefore also a lucky prime. 1987 is a prime factor of the 9th number in Sylvester's sequence, and is the 15th prime to divide any number in the sequence.

There are 1987 polyiamonds with 12 cells that tile the plane isohedrally.^[1]

In astronomy

• SN 1987A was a supernova first seen on February 23, 1987. It was the closest observed supernova since 1604.
• 1987 Kaplan is a main-belt asteroid discovered in 1952.
• NGC 1987 is a globular star cluster in the constellation Mensa.^[2]

In entertainment

• 1987 is the title of the European version of the album Whitesnake by the British rock band Whitesnake.
• 1987 (What the Fuck Is Going On?) is the debut album of the British band The Justified Ancients of Mu Mu (The JAMs: Bill Drummond and Jimmy Cauty).
• "1987" is the sixth episode of the second season of the television comedy series Robot Chicken.

In other fields

• UN 1987 is the UN number for the hazardous substance "Alcohols, n.o.s." (n.o.s. stands for not otherwise specified).^[3]
• There are 1987 ways to place 4 nonattacking chess kings on a 5 × 5 board.^[4]
• 1987 is the most recent year to have no repeating digits, the next being 2013

References

1. ^ (sequence A075223 in OEIS).
2. ^ Hartmut Frommert, "NGC 1987".
3. ^ National Oceanic and Atmospheric Administration, "Chemical data sheet for: ALCOHOLS, N.O.S.".
4. ^ (sequence A061997 in OEIS).