91931816 has 16 divisors (see below), whose sum is σ = 174080340. Its totient is φ = 45510400.

The previous prime is 91931813. The next prime is 91931843. The reversal of 91931816 is 61813919.

It can be written as a sum of positive squares in 2 ways, for example, as 91202500 + 729316 = 9550^2 + 854^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 91931816.

It is not an unprimeable number, because it can be changed into a prime (91931813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56081 + ... + 57696.

Almost surely, 2^91931816 is an apocalyptic number.

It is an amenable number.

91931816 is a deficient number, since it is larger than the sum of its proper divisors (82148524).

91931816 is a wasteful number, since it uses less digits than its factorization.

91931816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113884 (or 113880 counting only the distinct ones).

The product of its digits is 11664, while the sum is 38.

The square root of 91931816 is about 9588.1080511225. The cubic root of 91931816 is about 451.3241917284.

The spelling of 91931816 in words is "ninety-one million, nine hundred thirty-one thousand, eight hundred sixteen".