91331520 has 112 divisors (see below), whose sum is σ = 331427328. Its totient is φ = 20874240.

The previous prime is 91331509. The next prime is 91331567. The reversal of 91331520 is 2513319.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (112).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 76 + ... + 13515.

Almost surely, 2^91331520 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 91331520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (165713664).

91331520 is an abundant number, since it is smaller than the sum of its proper divisors (240095808).

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

91331520 is a wasteful number, since it uses less digits than its factorization.

91331520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13618 (or 13608 counting only the distinct ones).

The product of its (nonzero) digits is 810, while the sum is 24.

The square root of 91331520 is about 9556.7525865223. The cubic root of 91331520 is about 450.3396941259.

Adding to 91331520 its reverse (2513319), we get a palindrome (93844839).

The spelling of 91331520 in words is "ninety-one million, three hundred thirty-one thousand, five hundred twenty".