91831392 has 72 divisors (see below), whose sum is σ = 262112760. Its totient is φ = 30497280.

The previous prime is 91831391. The next prime is 91831403. The reversal of 91831392 is 29313819.

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 (36).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91831391) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 120292 + ... + 121052.

It is an arithmetic number, because the mean of its divisors is an integer number (3640455).

Almost surely, 2^91831392 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 91831392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (131056380).

91831392 is an abundant number, since it is smaller than the sum of its proper divisors (170281368).

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

91831392 is a wasteful number, since it uses less digits than its factorization.

91831392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1196 (or 1185 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 91831392 is about 9582.8697163219. The cubic root of 91831392 is about 451.1597934597.

The spelling of 91831392 in words is "ninety-one million, eight hundred thirty-one thousand, three hundred ninety-two".