11656511556 has 12 divisors (see below), whose sum is σ = 27198526992. Its totient is φ = 3885503848.

The previous prime is 11656511507. The next prime is 11656511597. The reversal of 11656511556 is 65511565611.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×11656511556² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 485687970 + ... + 485687993.

It is an arithmetic number, because the mean of its divisors is an integer number (2266543916).

Almost surely, 2^11656511556 is an apocalyptic number.

It is an amenable number.

11656511556 is an abundant number, since it is smaller than the sum of its proper divisors (15542015436).

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

11656511556 is a wasteful number, since it uses less digits than its factorization.

11656511556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 971375970 (or 971375968 counting only the distinct ones).

The product of its digits is 135000, while the sum is 42.

The spelling of 11656511556 in words is "eleven billion, six hundred fifty-six million, five hundred eleven thousand, five hundred fifty-six".