50 can be written using four 4's:
See also 113
50 has 6
divisors (see below), whose sum is σ = 93
Its totient is φ = 20
The previous prime is 47. The next prime is 53. The reversal of 50 is 5.
Added to its reverse (5) it gives a triangular number (55 = T10).
50 = 32 + 42 + 52.
50 is nontrivially palindromic in base 7 and base 9.
50 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
It is a Cunningham number, because it is equal to 72+1.
50 is an esthetic number in base 3, base 7 and base 16, because in such bases its adjacent digits differ by 1.
It is an interprime number because it is at equal distance from previous prime (47) and next prime (53).
It can be written as a sum of positive squares in 2 ways, for example, as 49 + 1 = 7^2 + 1^2
It is an ABA number since it can be written as A⋅BA, here for A=2, B=5.
It is a Harshad number since it is a multiple of its sum of digits (5).
It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.
It is a magnanimous number.
It is an alternating number because its digits alternate between odd and even.
It is a Duffinian number.
50 is an undulating number in base 3 and base 7.
It is a Curzon number.
50 is a nontrivial repdigit in base 9.
It is a plaindrome in base 6, base 9, base 11, base 13, base 14 and base 15.
It is a nialpdrome in base 5, base 8, base 9, base 10, base 12 and base 16.
It is a zygodrome in base 9.
It is a pernicious number, because its binary representation contains a prime number (3) of ones.
It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 8 + ... + 12.
50 is a deficient number, since it is larger than the sum of its proper divisors (43).
50 is a wasteful number, since it uses less digits than its factorization.
With its predecessor (49) it forms a Ruth-Aaron pair, since the sum of their distinct prime factors is the same (7).
50 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 12 (or 7 counting only the distinct ones).
The product of its (nonzero) digits is 5, while the sum is 5.
The square root of 50 is about 7.0710678119.
The cubic root of 50 is about 3.6840314986.
The spelling of 50 in words is "fifty", and thus it is an aban number, an eban number, an oban number, and an uban number.