509
This number is a prime.
The 509th Composite Group (an air combat unit of the U.S. Air Force) fulfilled its mission when the Enola Gay piloted by Colonel Tibbets dropped the first atomic bomb on Hiroshima. [McCranie]
509 was the number of the room in which the character Eve (played by Anne Baxter) in the movie "All About Eve" stayed in a hotel in New Haven. [Litman]
The sum of three consecutive squares (122 + 132 + 142). [Schlesinger]
509 millimetres is the record low annual rainfall in Perth (from 1940).
In the Clint Eastwood movie, "Firefox," 509 is the number
on the conning tower of the submarine beneath the ice pack.
In poker, there is one chance in 509 of receiving a flush (a mere flush, not a straight flush or a royal flush) when dealt 5 random cards from a deck of 52 playing cards. [Green]
The smallest Cyclops-Sophie Germain prime. [Pol]
The number of Josephus subsets of 9 people. [Post]
The repunit number of length 509 is known to be composite
but no factors are known.
The smallest multidigit octanacci prime number. (The
sequence of octanacci numbers starts with eight
predetermined terms, the first seven are zeros and the 8th
is 1, each term afterwards being the sum of the preceding
eight terms). [Loungrides]
The sum (p) of three consecutive squares up to and including the (5+0+9)th is 509. [Worrom]
The Fort Dix prime: because 509 is DIX in Roman numerals. [Gaydos]
According to tradition, in 509 BC the Roman monarchy was
overthrown and the Roman Republic era began. [Prisacariu]