11511565056 has 108 divisors (see below), whose sum is σ = 33645838408. Its totient is φ = 3784568832.

The previous prime is 11511565007. The next prime is 11511565057. The reversal of 11511565056 is 65056511511.

It is a happy number.

It is a super-2 number, since 2×11511565056² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 11511565056.

It is not an unprimeable number, because it can be changed into a prime (11511565057) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 133971 + ... + 202413.

Almost surely, 2^11511565056 is an apocalyptic number.

11511565056 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 11511565056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16822919204).

11511565056 is an abundant number, since it is smaller than the sum of its proper divisors (22134273352).

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

11511565056 is an equidigital number, since it uses as much as digits as its factorization.

11511565056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68538 (or 68521 counting only the distinct ones).

The product of its (nonzero) digits is 22500, while the sum is 36.

The spelling of 11511565056 in words is "eleven billion, five hundred eleven million, five hundred sixty-five thousand, fifty-six".