90887721920 has 28 divisors (see below), whose sum is σ = 216426388584. Its totient is φ = 36355088640.

The previous prime is 90887721887. The next prime is 90887721937. The reversal of 90887721920 is 2912778809.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 142011746 + ... + 142012385.

It is an arithmetic number, because the mean of its divisors is an integer number (7729513878).

Almost surely, 2^90887721920 is an apocalyptic number.

It is an amenable number.

90887721920 is an abundant number, since it is smaller than the sum of its proper divisors (125538666664).

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

90887721920 is a wasteful number, since it uses less digits than its factorization.

90887721920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284024148 (or 284024138 counting only the distinct ones).

The product of its (nonzero) digits is 1016064, while the sum is 53.

The spelling of 90887721920 in words is "ninety billion, eight hundred eighty-seven million, seven hundred twenty-one thousand, nine hundred twenty".