91631808 has 84 divisors (see below), whose sum is σ = 264093960. Its totient is φ = 30375936.

The previous prime is 91631803. The next prime is 91631809. The reversal of 91631808 is 80813619.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (91631801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 147723 + ... + 148341.

Almost surely, 2^91631808 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91631808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132046980).

91631808 is an abundant number, since it is smaller than the sum of its proper divisors (172462152).

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

91631808 is a wasteful number, since it uses less digits than its factorization.

91631808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 894 (or 881 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 91631808 is about 9572.4504699685. The cubic root of 91631808 is about 450.8327099993.

The spelling of 91631808 in words is "ninety-one million, six hundred thirty-one thousand, eight hundred eight".