91065172320 has 192 divisors, whose sum is σ = 320135639040. Its totient is φ = 24176807424.

The previous prime is 91065172307. The next prime is 91065172351. The reversal of 91065172320 is 2327156019.

91065172320 is a `hidden beast` number, since 9 + 106 + 517 + 2 + 32 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 934209 + ... + 1027071.

It is an arithmetic number, because the mean of its divisors is an integer number (1667373120).

Almost surely, 2^91065172320 is an apocalyptic number.

91065172320 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 91065172320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160067819520).

91065172320 is an abundant number, since it is smaller than the sum of its proper divisors (229070466720).

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

91065172320 is a wasteful number, since it uses less digits than its factorization.

91065172320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93114 (or 93100 counting only the distinct ones).

The product of its (nonzero) digits is 22680, while the sum is 36.

The spelling of 91065172320 in words is "ninety-one billion, sixty-five million, one hundred seventy-two thousand, three hundred twenty".