91161756564 has 12 divisors (see below), whose sum is σ = 212710765344. Its totient is φ = 30387252184.

The previous prime is 91161756547. The next prime is 91161756599. The reversal of 91161756564 is 46565716119.

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

It is a congruent number.

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, 3798406512 + ... + 3798406535.

It is an arithmetic number, because the mean of its divisors is an integer number (17725897112).

Almost surely, 2^91161756564 is an apocalyptic number.

It is an amenable number.

91161756564 is an abundant number, since it is smaller than the sum of its proper divisors (121549008780).

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

91161756564 is a wasteful number, since it uses less digits than its factorization.

91161756564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7596813054 (or 7596813052 counting only the distinct ones).

The product of its digits is 1360800, while the sum is 51.

The spelling of 91161756564 in words is "ninety-one billion, one hundred sixty-one million, seven hundred fifty-six thousand, five hundred sixty-four".