11571657972 has 96 divisors (see below), whose sum is σ = 32378271744. Its totient is φ = 3144873600.

The previous prime is 11571657967. The next prime is 11571657997. The reversal of 11571657972 is 27975617511.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 333147 + ... + 366237.

It is an arithmetic number, because the mean of its divisors is an integer number (337273664).

Almost surely, 2^11571657972 is an apocalyptic number.

11571657972 is a gapful number since it is divisible by the number (12) 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 11571657972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16189135872).

11571657972 is an abundant number, since it is smaller than the sum of its proper divisors (20806613772).

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

11571657972 is a wasteful number, since it uses less digits than its factorization.

11571657972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33309 (or 33307 counting only the distinct ones).

The product of its digits is 926100, while the sum is 51.

The spelling of 11571657972 in words is "eleven billion, five hundred seventy-one million, six hundred fifty-seven thousand, nine hundred seventy-two".