91979278162775 has 24 divisors (see below), whose sum is σ = 115902167500800. Its totient is φ = 72395580437600.

The previous prime is 91979278162771. The next prime is 91979278162799. The reversal of 91979278162775 is 57726187297919.

It is not a de Polignac number, because 91979278162775 - 2² = 91979278162771 is a prime.

It is a super-2 number, since 2×91979278162775² (a number of 29 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 91979278162775.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91979278162771) 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, 53240915 + ... + 54941364.

It is an arithmetic number, because the mean of its divisors is an integer number (4829256979200).

Almost surely, 2^{91979278162775} is an apocalyptic number.

91979278162775 is a deficient number, since it is larger than the sum of its proper divisors (23922889338025).

91979278162775 is a wasteful number, since it uses less digits than its factorization.

91979278162775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108182839 (or 108182834 counting only the distinct ones).

The product of its digits is 1680315840, while the sum is 80.

The spelling of 91979278162775 in words is "ninety-one trillion, nine hundred seventy-nine billion, two hundred seventy-eight million, one hundred sixty-two thousand, seven hundred seventy-five".