51521 has 2 divisors, whose sum is σ = 51522.
Its totient is φ = 51520.
The previous prime is 51517. The next prime is 51539. The reversal of 51521 is 12515.
51521 = 1602 + 1612.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 25921 + 25600 = 161^2 + 160^2
It is a cyclic number.
It is not a de Polignac number, because 51521 - 22 = 51517 is a prime.
It is a Sophie Germain prime.
It is a Chen prime.
It is an Ulam number.
It is a Curzon number.
It is a plaindrome in base 11.
It is a nialpdrome in base 16.
It is a junction number, because it is equal to n+sod(n) for n = 51496 and 51505.
It is not a weakly prime, because it can be changed into another prime (51511) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25760 + 25761.
It is an arithmetic number, because the mean of its divisors is an integer number (25761).
251521 is an apocalyptic number.
51521 is the 161-st centered square number.
It is an amenable number.
51521 is a deficient number, since it is larger than the sum of its proper divisors (1).
51521 is an equidigital number, since it uses as much as digits as its factorization.
51521 is an evil number, because the sum of its binary digits is even.
The product of its digits is 50, while the sum is 14.
The square root of 51521 is about 226.9823781706.
The cubic root of 51521 is about 37.2101506196.
The spelling of 51521 in words is "fifty-one thousand, five hundred twenty-one".