91912320 has 224 divisors, whose sum is σ = 331113420. Its totient is φ = 24385536.

The previous prime is 91912309. The next prime is 91912361. The reversal of 91912320 is 2321919.

It can be written as a sum of positive squares in 2 ways, for example, as 86266944 + 5645376 = 9288^2 + 2376^2 .

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

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

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 466462 + ... + 466658.

Almost surely, 2^91912320 is an apocalyptic number.

91912320 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91912320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (165556710).

91912320 is an abundant number, since it is smaller than the sum of its proper divisors (239201100).

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

91912320 is an equidigital number, since it uses as much as digits as its factorization.

91912320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234 (or 207 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 91912320 is about 9587.0913211464. The cubic root of 91912320 is about 451.2922853334.

It can be divided in two parts, 9191 and 2320, that added together give a palindrome (11511).

The spelling of 91912320 in words is "ninety-one million, nine hundred twelve thousand, three hundred twenty".