91079440128 has 108 divisors (see below), whose sum is σ = 262747390360. Its totient is φ = 30343292928.

The previous prime is 91079440097. The next prime is 91079440141. The reversal of 91079440128 is 82104497019.

It is a happy number.

91079440128 is a `hidden beast` number, since 9 + 10 + 79 + 440 + 128 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4665075 + ... + 4684557.

Almost surely, 2^91079440128 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 91079440128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (131373695180).

91079440128 is an abundant number, since it is smaller than the sum of its proper divisors (171667950232).

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

91079440128 is a wasteful number, since it uses less digits than its factorization.

91079440128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21534 (or 21517 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The spelling of 91079440128 in words is "ninety-one billion, seventy-nine million, four hundred forty thousand, one hundred twenty-eight".