91811232 has 72 divisors (see below), whose sum is σ = 270781056. Its totient is φ = 30601152.

The previous prime is 91811227. The next prime is 91811261. The reversal of 91811232 is 23211819.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 91811196 and 91811205.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1873 + ... + 13679.

It is an arithmetic number, because the mean of its divisors is an integer number (3760848).

Almost surely, 2^91811232 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 91811232, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135390528).

91811232 is an abundant number, since it is smaller than the sum of its proper divisors (178969824).

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

91811232 is a wasteful number, since it uses less digits than its factorization.

91811232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11832 (or 11812 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 91811232 is about 9581.8177816112. The cubic root of 91811232 is about 451.1267762568.

The spelling of 91811232 in words is "ninety-one million, eight hundred eleven thousand, two hundred thirty-two".