56651661 has 12 divisors (see below), whose sum is σ = 89269440. Its totient is φ = 34334280.

The previous prime is 56651657. The next prime is 56651687. The reversal of 56651661 is 16615665.

It is not a de Polignac number, because 56651661 - 2² = 56651657 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56651261) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 286021 + ... + 286218.

It is an arithmetic number, because the mean of its divisors is an integer number (7439120).

Almost surely, 2^56651661 is an apocalyptic number.

It is an amenable number.

56651661 is a deficient number, since it is larger than the sum of its proper divisors (32617779).

56651661 is a wasteful number, since it uses less digits than its factorization.

56651661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 572256 (or 572253 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 56651661 is about 7526.7297679670. The cubic root of 56651661 is about 384.0645440009.

The spelling of 56651661 in words is "fifty-six million, six hundred fifty-one thousand, six hundred sixty-one".