50 (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 = 1
2 + 7
2 = 5
2 + 5
2. It is also the sum of three squares, 50 = 3
2 + 4
2 + 5
2, and the sum of four squares, 50 = 6
2 + 3
2 + 2
2 + 1
2. It is a
Harshad number
In mathematics, a harshad number (or Niven number) in a given number base is an integer that is divisible by the sum of its digits when written in that base.
Harshad numbers in base are also known as -harshad (or -Niven) numbers.
Harshad numbers ...
.
50 is a
Stirling number of the first kind
In mathematics, especially in combinatorics, Stirling numbers of the first kind arise in the study of permutations. In particular, the Stirling numbers of the first kind count permutations according to their number of cycles (counting fixed poin ...
:
and also a
Narayana number:
There is no solution to the equation
φ(''x'') = 50, making 50 a
nontotient. Nor is there a solution to the equation ''x'' − φ(''x'') = 50, making 50 a
noncototient.
In science
*The
atomic number of
tin
*The fifth
magic number in nuclear physics
In religion
*In
Kabbalah, there are 50 Gates of Wisdom (or Understanding) and 50 Gates of Impurity
*The traditional number of years in a
jubilee period.
[Leviticus 25:10]
*The Christian Feast of
Pentecost
Pentecost (also called Whit Sunday, Whitsunday or Whitsun) is a Christianity, Christian holiday which takes place on the 50th day (the seventh Sunday) after Easter Sunday. It commemorates the descent of the Holy Spirit upon the Apostles in the Ne ...
takes place on the 50th day of the
Easter Season
*The Jewish
Pentecost
Pentecost (also called Whit Sunday, Whitsunday or Whitsun) is a Christianity, Christian holiday which takes place on the 50th day (the seventh Sunday) after Easter Sunday. It commemorates the descent of the Holy Spirit upon the Apostles in the Ne ...
takes place 50 days after the
Passover feast (the holiday of
Shavuoth).
In sports
* In cricket
one day internationals, each side may bat for 50 overs.
In other fields
Fifty is:
* There are 50 states in the United States of America.
* The TV show ''
Hawaii Five-O'' and its reimagined version, ''
Hawaii Five-0
Hawaii Five-O or Hawaii Five-0 may refer to:
* Hawaii Five-0 (2010 TV series), ''Hawaii Five-0'' (2010 TV series), an American action police procedural television series
* Hawaii Five-O (1968 TV series), ''Hawaii Five-O'' (1968 TV series), an Ame ...
'', 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''
* A calibre of ammunition (0.50 inches: see
.50 BMG)
* In millimetres, the
focal length
The focal length of an optical system is a measure of how strongly the system converges or diverges light; it is the inverse of the system's optical power. A positive focal length indicates that a system converges light, while a negative foca ...
of the normal lens in 35 mm photography
* The
percentage
In mathematics, a percentage (from la, per centum, "by a hundred") is a number or ratio expressed as a fraction of 100. It is often denoted using the percent sign, "%", although the abbreviations "pct.", "pct" and sometimes "pc" are also us ...
(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
* In years of marriage, the gold or "golden"
wedding anniversary
* The speed limit, in kilometres per hour, of Australian and Canadian roads with unspecified limits.
See also
*
List of highways numbered 50
References
{{DEFAULTSORT:50 (Number)
*
Integers