← 49 50 51 →
Cardinalfifty
Ordinal50th
(fiftieth)
Numeral systemquinquagesimal
Factorization2 × 52
Divisors1, 2, 5, 10, 25, 50
Greek numeralΝ´
Roman numeralL
Unicode symbol(s)
Binary1100102
Ternary12123
Senary1226
Octal628
Duodecimal4212
Hexadecimal3216

50 (fifty) is the natural number following 49 and preceding 51.

In mathematics

50 as the sum of two non-zero squares

Fifty is the smallest number that is the sum of two non-zero square numbers in two distinct ways: 50 = 12 + 72 = 52 + 52 (see image).[1] It is also the sum of three squares, 50 = 32 + 42 + 52, and the sum of four squares, 50 = 62 + 32 + 22 + 12. It is a Harshad number.[2]

50 is a Stirling number of the first kind: and also a Narayana number:

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 science

In religion

In sports

In other fields

Fifty is:

Businesses

See also

References

  1. ^ de Koninck, J.M. (2009). Those fascinating numbers. AMS Bookstore. p. 18. ISBN 0-8218-4807-0.
  2. ^ "Sloane's A005349 : Niven (or Harshad) numbers". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-30.
  3. ^ "Sloane's A005277 : Nonients". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-30.
  4. ^ "Sloane's A005278 : Noncotients". The On-Line Encyclopedia of Integer Sequences. OEIS Foundation. Retrieved 2016-05-30.
  5. ^ Leviticus 25:10
  6. ^ 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.