91817320 has 64 divisors (see below), whose sum is σ = 241159680. Its totient is φ = 30806016.

The previous prime is 91817309. The next prime is 91817353. The reversal of 91817320 is 2371819.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9672 + ... + 16648.

It is an arithmetic number, because the mean of its divisors is an integer number (3768120).

Almost surely, 2^91817320 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 91817320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120579840).

91817320 is an abundant number, since it is smaller than the sum of its proper divisors (149342360).

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

91817320 is a wasteful number, since it uses less digits than its factorization.

91817320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7042 (or 7038 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 91817320 is about 9582.1354613677. The cubic root of 91817320 is about 451.1367474374.

The spelling of 91817320 in words is "ninety-one million, eight hundred seventeen thousand, three hundred twenty".