56631561 has 16 divisors (see below), whose sum is σ = 86421888. Its totient is φ = 32313600.

The previous prime is 56631557. The next prime is 56631581. The reversal of 56631561 is 16513665.

56631561 is nontrivially palindromic in base 14.

It is not a de Polignac number, because 56631561 - 2² = 56631557 is a prime.

It is not an unprimeable number, because it can be changed into a prime (56631511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16971 + ... + 20031.

It is an arithmetic number, because the mean of its divisors is an integer number (5401368).

Almost surely, 2^56631561 is an apocalyptic number.

It is an amenable number.

56631561 is a deficient number, since it is larger than the sum of its proper divisors (29790327).

56631561 is a wasteful number, since it uses less digits than its factorization.

56631561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3952.

The product of its digits is 16200, while the sum is 33.

The square root of 56631561 is about 7525.3944082686. The cubic root of 56631561 is about 384.0191166156.

The spelling of 56631561 in words is "fifty-six million, six hundred thirty-one thousand, five hundred sixty-one".