A page of the Numeropedia - the Special Encyclopedia of Numbers
[Calendar] The minimum number of complete (full) weeks within in a calendar year.
[Chemistry] The atomic number of Antimony (Sb).
[Tech.] 51(W, KW or MW) is one of standard numerical values for resistors (of tolerance class 5%). 51pF (picofarads) is one of standard numerical values for capacitors.
[Math.] Its odd powers end with 51. Its even powers end with 01.
[Math.] 513 = 132,651 = (–13–2+65+1)3 = (–1–3–2+6+51)3.
[Math.] A regular polygon with this odd number (product of Fermat prime numbers) of sides is constructible by using only straightedge and compass. 51 = 3´17.
[Money] A MasterCard credit card number starts with either 2 digits 51, 52, 53, 54 or 55.
[Movie] Name of TV show/series/movies: “The 51st State” and “Showdown at Area 51”.
[Phone] International telephone dialing code for Peru.
[Phone] The emergency telephone number dialing within Moscow, Russia.
[Science] The number 1051 is sexdecillion, in American system. In British system, sexdecillion is 1096.
[Trivia] U.S. Air Force’s secret test facility at Groom Lake, Nevada is usually referred as “Area 51”.
[World] The ISO-3166 country code for Armenia is 051.