91909944 has 128 divisors (see below), whose sum is σ = 295488000. Its totient is φ = 25926912.

The previous prime is 91909931. The next prime is 91909969. The reversal of 91909944 is 44990919.

It is a self number, because there is not a number n which added to its sum of digits gives 91909944.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 134227 + ... + 134909.

It is an arithmetic number, because the mean of its divisors is an integer number (2308500).

Almost surely, 2^91909944 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 91909944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147744000).

91909944 is an abundant number, since it is smaller than the sum of its proper divisors (203578056).

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

91909944 is a wasteful number, since it uses less digits than its factorization.

91909944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 794 (or 784 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 45.

The square root of 91909944 is about 9586.9674037205. The cubic root of 91909944 is about 451.2883965558.

The spelling of 91909944 in words is "ninety-one million, nine hundred nine thousand, nine hundred forty-four".