91261011872 has 36 divisors (see below), whose sum is σ = 190860662790. Its totient is φ = 42946354176.

The previous prime is 91261011851. The next prime is 91261011887. The reversal of 91261011872 is 27811016219.

It can be written as a sum of positive squares in 3 ways, for example, as 87282430096 + 3978581776 = 295436^2 + 63076^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4924847 + ... + 4943342.

Almost surely, 2^91261011872 is an apocalyptic number.

It is an amenable number.

91261011872 is an abundant number, since it is smaller than the sum of its proper divisors (99599650918).

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

91261011872 is a wasteful number, since it uses less digits than its factorization.

91261011872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9868233 (or 9868208 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 38.

The spelling of 91261011872 in words is "ninety-one billion, two hundred sixty-one million, eleven thousand, eight hundred seventy-two".