91500640 has 144 divisors (see below), whose sum is σ = 274582224. Its totient is φ = 28492800.

The previous prime is 91500571. The next prime is 91500653. The reversal of 91500640 is 4600519.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 85710 + ... + 86770.

It is an arithmetic number, because the mean of its divisors is an integer number (1906821).

Almost surely, 2^91500640 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 91500640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137291112).

91500640 is an abundant number, since it is smaller than the sum of its proper divisors (183081584).

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

91500640 is a wasteful number, since it uses less digits than its factorization.

91500640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1101 (or 1086 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 91500640 is about 9565.5966881319. The cubic root of 91500640 is about 450.6174897419.

The spelling of 91500640 in words is "ninety-one million, five hundred thousand, six hundred forty".