91432640 has 112 divisors (see below), whose sum is σ = 242376960. Its totient is φ = 32624640.

The previous prime is 91432631. The next prime is 91432643. The reversal of 91432640 is 4623419.

It is not an unprimeable number, because it can be changed into a prime (91432643) 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, 128606 + ... + 129314.

It is an arithmetic number, because the mean of its divisors is an integer number (2164080).

Almost surely, 2^91432640 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 91432640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121188480).

91432640 is an abundant number, since it is smaller than the sum of its proper divisors (150944320).

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

91432640 is a wasteful number, since it uses less digits than its factorization.

91432640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 770 (or 760 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 91432640 is about 9562.0416230008. The cubic root of 91432640 is about 450.5058344824.

The spelling of 91432640 in words is "ninety-one million, four hundred thirty-two thousand, six hundred forty".