56991565 has 8 divisors (see below), whose sum is σ = 72412920. Its totient is φ = 42911232.

The previous prime is 56991559. The next prime is 56991587. The reversal of 56991565 is 56519965.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 12981609 + 44009956 = 3603^2 + 6634^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-56991565 is a prime.

It is a super-2 number, since 2×56991565² = 6496076962298450, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 335160 + ... + 335329.

It is an arithmetic number, because the mean of its divisors is an integer number (9051615).

Almost surely, 2^56991565 is an apocalyptic number.

It is an amenable number.

56991565 is a deficient number, since it is larger than the sum of its proper divisors (15421355).

56991565 is a wasteful number, since it uses less digits than its factorization.

56991565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 670511.

The product of its digits is 364500, while the sum is 46.

The square root of 56991565 is about 7549.2757930811. The cubic root of 56991565 is about 384.8311285029.

The spelling of 56991565 in words is "fifty-six million, nine hundred ninety-one thousand, five hundred sixty-five".