91517972 has 48 divisors (see below), whose sum is σ = 199110912. Its totient is φ = 35838720.

The previous prime is 91517971. The next prime is 91518029. The reversal of 91517972 is 27971519.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91517971) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36272 + ... + 38712.

It is an arithmetic number, because the mean of its divisors is an integer number (4148144).

Almost surely, 2^91517972 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 91517972, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99555456).

91517972 is an abundant number, since it is smaller than the sum of its proper divisors (107592940).

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

91517972 is a wasteful number, since it uses less digits than its factorization.

91517972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2568 (or 2566 counting only the distinct ones).

The product of its digits is 39690, while the sum is 41.

The square root of 91517972 is about 9566.5026002192. The cubic root of 91517972 is about 450.6459398499.

The spelling of 91517972 in words is "ninety-one million, five hundred seventeen thousand, nine hundred seventy-two".