56511021551 has 16 divisors (see below), whose sum is σ = 60347358720. Its totient is φ = 52803606240.

The previous prime is 56511021533. The next prime is 56511021577. The reversal of 56511021551 is 15512011565.

56511021551 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 56511021551 - 2¹⁸ = 56510759407 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 (56511921551) 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, 19256 + ... + 336738.

It is an arithmetic number, because the mean of its divisors is an integer number (3771709920).

Almost surely, 2^56511021551 is an apocalyptic number.

56511021551 is a deficient number, since it is larger than the sum of its proper divisors (3836337169).

56511021551 is a wasteful number, since it uses less digits than its factorization.

56511021551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317686.

The product of its (nonzero) digits is 7500, while the sum is 32.

The spelling of 56511021551 in words is "fifty-six billion, five hundred eleven million, twenty-one thousand, five hundred fifty-one".