56591209566 has 48 divisors (see below), whose sum is σ = 130622768640. Its totient is φ = 17655587280.

The previous prime is 56591209529. The next prime is 56591209601. The reversal of 56591209566 is 66590219565.

56591209566 is a `hidden beast` number, since 5 + 6 + 59 + 1 + 20 + 9 + 566 = 666.

56591209566 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 968430 + ... + 1025201.

It is an arithmetic number, because the mean of its divisors is an integer number (2721307680).

Almost surely, 2^56591209566 is an apocalyptic number.

56591209566 is an abundant number, since it is smaller than the sum of its proper divisors (74031559074).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

56591209566 is a wasteful number, since it uses less digits than its factorization.

56591209566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1993741 (or 1993738 counting only the distinct ones).

The product of its (nonzero) digits is 4374000, while the sum is 54.

Subtracting 56591209566 from its reverse (66590219565), we obtain a palindrome (9999009999).

The spelling of 56591209566 in words is "fifty-six billion, five hundred ninety-one million, two hundred nine thousand, five hundred sixty-six".