91987868 has 24 divisors (see below), whose sum is σ = 184377984. Its totient is φ = 39337200.

The previous prime is 91987843. The next prime is 91987877. The reversal of 91987868 is 86878919.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10403 + ... + 17093.

It is an arithmetic number, because the mean of its divisors is an integer number (7682416).

Almost surely, 2^91987868 is an apocalyptic number.

It is an amenable number.

91987868 is an abundant number, since it is smaller than the sum of its proper divisors (92390116).

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

91987868 is a wasteful number, since it uses less digits than its factorization.

91987868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7193 (or 7191 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 56.

The square root of 91987868 is about 9591.0306015569. The cubic root of 91987868 is about 451.4158991300.

The spelling of 91987868 in words is "ninety-one million, nine hundred eighty-seven thousand, eight hundred sixty-eight".