91799931 has 4 divisors (see below), whose sum is σ = 122399912. Its totient is φ = 61199952.

The previous prime is 91799843. The next prime is 91799951. The reversal of 91799931 is 13999719.

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

It is not a de Polignac number, because 91799931 - 2⁷ = 91799803 is a prime.

It is a super-2 number, since 2×91799931² = 16854454663209522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91799951) 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, 15299986 + ... + 15299991.

It is an arithmetic number, because the mean of its divisors is an integer number (30599978).

Almost surely, 2^91799931 is an apocalyptic number.

91799931 is a deficient number, since it is larger than the sum of its proper divisors (30599981).

91799931 is a wasteful number, since it uses less digits than its factorization.

91799931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30599980.

The product of its digits is 137781, while the sum is 48.

The square root of 91799931 is about 9581.2280528124. The cubic root of 91799931 is about 451.1082658387.

It can be divided in two parts, 9179 and 9931, that added together give a triangular number (19110 = T₁₉₅).

The spelling of 91799931 in words is "ninety-one million, seven hundred ninety-nine thousand, nine hundred thirty-one".