91637564928 has 960 divisors, whose sum is σ = 327810447360. Its totient is φ = 22221029376.

The previous prime is 91637564903. The next prime is 91637564939. The reversal of 91637564928 is 82946573619.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1949735401 + ... + 1949735447.

It is an arithmetic number, because the mean of its divisors is an integer number (341469216).

Almost surely, 2^91637564928 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 91637564928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (163905223680).

91637564928 is an abundant number, since it is smaller than the sum of its proper divisors (236172882432).

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

91637564928 is a wasteful number, since it uses less digits than its factorization.

91637564928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167 (or 138 counting only the distinct ones).

The product of its digits is 19595520, while the sum is 60.

The spelling of 91637564928 in words is "ninety-one billion, six hundred thirty-seven million, five hundred sixty-four thousand, nine hundred twenty-eight".