91791897 has 16 divisors (see below), whose sum is σ = 124027200. Its totient is φ = 60381632.

The previous prime is 91791877. The next prime is 91791901. The reversal of 91791897 is 79819719.

It is a cyclic number.

It is not a de Polignac number, because 91791897 - 2¹⁴ = 91775513 is a prime.

Its product of digits (285768) is a multiple of the sum of its prime divisors (1512).

It is not an unprimeable number, because it can be changed into a prime (91791877) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 76738 + ... + 77924.

It is an arithmetic number, because the mean of its divisors is an integer number (7751700).

Almost surely, 2^91791897 is an apocalyptic number.

It is an amenable number.

91791897 is a deficient number, since it is larger than the sum of its proper divisors (32235303).

91791897 is a wasteful number, since it uses less digits than its factorization.

91791897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1512.

The product of its digits is 285768, while the sum is 51.

The square root of 91791897 is about 9580.8087863186. The cubic root of 91791897 is about 451.0951056634.

The spelling of 91791897 in words is "ninety-one million, seven hundred ninety-one thousand, eight hundred ninety-seven".