91973756961 has 24 divisors (see below), whose sum is σ = 137798204544. Its totient is φ = 61303903920.

The previous prime is 91973756939. The next prime is 91973756981. The reversal of 91973756961 is 16965737919.

91973756961 is a `hidden beast` number, since 9 + 1 + 9 + 7 + 3 + 7 + 569 + 61 = 666.

It is not a de Polignac number, because 91973756961 - 2⁵ = 91973756929 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91973756981) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1316296 + ... + 1384406.

It is an arithmetic number, because the mean of its divisors is an integer number (5741591856).

Almost surely, 2^91973756961 is an apocalyptic number.

It is an amenable number.

91973756961 is a deficient number, since it is larger than the sum of its proper divisors (45824447583).

91973756961 is an equidigital number, since it uses as much as digits as its factorization.

91973756961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73683 (or 73671 counting only the distinct ones).

The product of its digits is 19289340, while the sum is 63.

The spelling of 91973756961 in words is "ninety-one billion, nine hundred seventy-three million, seven hundred fifty-six thousand, nine hundred sixty-one".