91807872 has 128 divisors (see below), whose sum is σ = 268349760. Its totient is φ = 27635712.

The previous prime is 91807843. The next prime is 91807879. The reversal of 91807872 is 27870819.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×91807872² = 16857370722336768, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (91807879) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 264403 + ... + 264749.

Almost surely, 2^91807872 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 91807872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (134174880).

91807872 is an abundant number, since it is smaller than the sum of its proper divisors (176541888).

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

91807872 is a wasteful number, since it uses less digits than its factorization.

91807872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 430 (or 418 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 42.

The square root of 91807872 is about 9581.6424479314. The cubic root of 91807872 is about 451.1212729198.

The spelling of 91807872 in words is "ninety-one million, eight hundred seven thousand, eight hundred seventy-two".