91225617680 has 40 divisors (see below), whose sum is σ = 212618218200. Its totient is φ = 36401015808.

The previous prime is 91225617667. The next prime is 91225617697. The reversal of 91225617680 is 8671652219.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 53141314576 + 38084303104 = 230524^2 + 195152^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×91225617680² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1361315 + ... + 1426754.

It is an arithmetic number, because the mean of its divisors is an integer number (5315455455).

Almost surely, 2^91225617680 is an apocalyptic number.

It is an amenable number.

91225617680 is an abundant number, since it is smaller than the sum of its proper divisors (121392600520).

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

91225617680 is a wasteful number, since it uses less digits than its factorization.

91225617680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2788491 (or 2788485 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 47.

The spelling of 91225617680 in words is "ninety-one billion, two hundred twenty-five million, six hundred seventeen thousand, six hundred eighty".