91997912166 has 32 divisors (see below), whose sum is σ = 190895367168. Its totient is φ = 29526090720.

The previous prime is 91997912131. The next prime is 91997912203. The reversal of 91997912166 is 66121979919.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1218720 + ... + 1292003.

It is an arithmetic number, because the mean of its divisors is an integer number (5965480224).

Almost surely, 2^91997912166 is an apocalyptic number.

91997912166 is an abundant number, since it is smaller than the sum of its proper divisors (98897455002).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91997912166 is a wasteful number, since it uses less digits than its factorization.

91997912166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2510956.

The product of its digits is 3306744, while the sum is 60.

The spelling of 91997912166 in words is "ninety-one billion, nine hundred ninety-seven million, nine hundred twelve thousand, one hundred sixty-six".