91979364961 has 27 divisors (see below), whose sum is σ = 102691490643. Its totient is φ = 82322594640.

The previous prime is 91979364899. The next prime is 91979364991. The reversal of 91979364961 is 16946397919.

The square root of 91979364961 is 303281.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 67512148561 + 24467216400 = 259831^2 + 156420^2 .

It is not a de Polignac number, because 91979364961 - 2¹³ = 91979356769 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 91979364893 and 91979364902.

It is not an unprimeable number, because it can be changed into a prime (91979364991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 263551015 + ... + 263551363.

Almost surely, 2^91979364961 is an apocalyptic number.

91979364961 is the 303281-st square number.

91979364961 is the 151641-st centered octagonal number.

It is an amenable number.

91979364961 is a deficient number, since it is larger than the sum of its proper divisors (10712125682).

91979364961 is an frugal number, since it uses more digits than its factorization.

91979364961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 878 (or 439 counting only the distinct ones).

The product of its digits is 19840464, while the sum is 64.

Multiplying 91979364961 by its sum of digits (64), we get a square (5886679357504 = 2426248²).

The spelling of 91979364961 in words is "ninety-one billion, nine hundred seventy-nine million, three hundred sixty-four thousand, nine hundred sixty-one".