91979388 has 42 divisors (see below), whose sum is σ = 241343144. Its totient is φ = 30658824.

The previous prime is 91979347. The next prime is 91979411. The reversal of 91979388 is 88397919.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 12856 + ... + 18687.

Almost surely, 2^91979388 is an apocalyptic number.

It is an amenable number.

91979388 is an abundant number, since it is smaller than the sum of its proper divisors (149363756).

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

91979388 is a wasteful number, since it uses less digits than its factorization.

91979388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31565 (or 31548 counting only the distinct ones).

The product of its digits is 979776, while the sum is 54.

The square root of 91979388 is about 9590.5885116608. The cubic root of 91979388 is about 451.4020272846.

The spelling of 91979388 in words is "ninety-one million, nine hundred seventy-nine thousand, three hundred eighty-eight".