56921521 has 2 divisors, whose sum is σ = 56921522. Its totient is φ = 56921520.

The previous prime is 56921509. The next prime is 56921563. The reversal of 56921521 is 12512965.

56921521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56175025 + 746496 = 7495^2 + 864^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56921521 is a prime.

It is not a weakly prime, because it can be changed into another prime (56921581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28460760 + 28460761.

It is an arithmetic number, because the mean of its divisors is an integer number (28460761).

Almost surely, 2^56921521 is an apocalyptic number.

It is an amenable number.

56921521 is a deficient number, since it is larger than the sum of its proper divisors (1).

56921521 is an equidigital number, since it uses as much as digits as its factorization.

56921521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5400, while the sum is 31.

The square root of 56921521 is about 7544.6352463191. The cubic root of 56921521 is about 384.6734083096.

The spelling of 56921521 in words is "fifty-six million, nine hundred twenty-one thousand, five hundred twenty-one".