56565661 has 4 divisors (see below), whose sum is σ = 56582524. Its totient is φ = 56548800.

The previous prime is 56565617. The next prime is 56565667. The reversal of 56565661 is 16656565.

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

It can be written as a sum of positive squares in 2 ways, for example, as 17690436 + 38875225 = 4206^2 + 6235^2 .

It is a cyclic number.

It is not a de Polignac number, because 56565661 - 2¹¹ = 56563613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56565667) 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, 1500 + ... + 10741.

It is an arithmetic number, because the mean of its divisors is an integer number (14145631).

Almost surely, 2^56565661 is an apocalyptic number.

56565661 is the 3364-th centered decagonal number.

It is an amenable number.

56565661 is a deficient number, since it is larger than the sum of its proper divisors (16863).

56565661 is a wasteful number, since it uses less digits than its factorization.

56565661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16862.

The product of its digits is 162000, while the sum is 40.

The square root of 56565661 is about 7521.0146257004. The cubic root of 56565661 is about 383.8701026388.

The spelling of 56565661 in words is "fifty-six million, five hundred sixty-five thousand, six hundred sixty-one".