91923608891 has 4 divisors (see below), whose sum is σ = 92080208472. Its totient is φ = 91767009312.

The previous prime is 91923608879. The next prime is 91923608911. The reversal of 91923608891 is 19880632919.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91923608891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91923608591) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 78298910 + ... + 78300083.

It is an arithmetic number, because the mean of its divisors is an integer number (23020052118).

Almost surely, 2^91923608891 is an apocalyptic number.

91923608891 is a deficient number, since it is larger than the sum of its proper divisors (156599581).

91923608891 is a wasteful number, since it uses less digits than its factorization.

91923608891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156599580.

The product of its (nonzero) digits is 1679616, while the sum is 56.

The spelling of 91923608891 in words is "ninety-one billion, nine hundred twenty-three million, six hundred eight thousand, eight hundred ninety-one".