(fifty) is the natural number following 49 and preceding 51.
In mathematics
Fifty is the smallest number that is the sum of two non-zero square numbers in two distinct ways: 50 = 12 + 72 = 52 + 52 (the former is the sum of squares of divisors of 7).[1] It is also the sum of three squares, 50 = 32 + 42 + 52 (that feature in the smallest Pythagorean triple), and the sum of four squares, 50 = 62 + 32 + 22 + 12 (as the squares of divisors of 6).[2]
There is no solution to the equation φ(x) = 50, making 50 a nontotient.[3] Nor is there a solution to the equation x − φ(x) = 50, making 50 a noncototient.[4]
Fifty is the sum of the number of faces that make up the Platonic solids (4 + 6 + 8 + 12 + 20 = 50).
In Hindu tantric tradition, the number 50 holds significance as the 50 Rudras in the Malinīvijayottara correlate with the 50 phonemes of Sanskrit, as well as with the 50 severed heads worn around goddess Kali's head. The mantraAham ("I am"), as laid out in the Vijñāna Bhairava represents the first अ(a) and last ह(ha) phonemes of the Sanskrit alphabet and is believed to represent ultimate reality, in accordance with its non-dual philosophy.
There are 50 states in the United States of America.
The TV show Hawaii Five-O and its reimagined version, Hawaii Five-0, are so called because Hawaii is the last (50th) of the states to officially become a state.
5-O (Five-Oh) - Slang for police officers and/or a warning that police are approaching. Derived from the television show Hawaii Five-O[6]
A calibre of ammunition (0.50 inches: see .50 BMG)
In millimetres, the focal length of the normal lens in 35 mm photography
The percentage (50%) equivalent to one half, so that the phrase "fifty-fifty" commonly expresses something divided equally in two; in business this is often denoted as being the ultimate in equal partnership
Fifty (outlet store) - Formerly "Fifty Outlet". Outlet stores, mostly in Spain, owned by Tendam, selling its brands e.g. Cortefiel, Springfield, and others'
^"Sloane's A005277 : Nonients". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-30.
^"Sloane's A005278 : Noncotients". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-30.
^Leviticus 25:10
^Karen Rhodes (1 February 1997). Booking Hawaii Five-O: An Episode Guide and Critical History of the 1968–1980 Television Detective Series. McFarland. p. 265. ISBN 978-0-7864-8666-3.