56515631 has 4 divisors (see below), whose sum is σ = 57829992. Its totient is φ = 55201272.

The previous prime is 56515607. The next prime is 56515637. The reversal of 56515631 is 13651565.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 56515631 - 2²² = 52321327 is a prime.

It is a super-2 number, since 2×56515631² = 6388033094656322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56515637) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 657116 + ... + 657201.

It is an arithmetic number, because the mean of its divisors is an integer number (14457498).

Almost surely, 2^56515631 is an apocalyptic number.

56515631 is a deficient number, since it is larger than the sum of its proper divisors (1314361).

56515631 is a wasteful number, since it uses less digits than its factorization.

56515631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1314360.

The product of its digits is 13500, while the sum is 32.

The square root of 56515631 is about 7517.6878759363. The cubic root of 56515631 is about 383.7568968193.

The spelling of 56515631 in words is "fifty-six million, five hundred fifteen thousand, six hundred thirty-one".