91939428 has 96 divisors (see below), whose sum is σ = 281272320. Its totient is φ = 25414560.

The previous prime is 91939411. The next prime is 91939433. The reversal of 91939428 is 82493919.

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, 21475 + ... + 25397.

It is an arithmetic number, because the mean of its divisors is an integer number (2929920).

Almost surely, 2^91939428 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 91939428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (140636160).

91939428 is an abundant number, since it is smaller than the sum of its proper divisors (189332892).

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

91939428 is a wasteful number, since it uses less digits than its factorization.

91939428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3974 (or 3966 counting only the distinct ones).

The product of its digits is 139968, while the sum is 45.

The square root of 91939428 is about 9588.5049929590. The cubic root of 91939428 is about 451.3366480070.

The spelling of 91939428 in words is "ninety-one million, nine hundred thirty-nine thousand, four hundred twenty-eight".