90915421720 has 32 divisors (see below), whose sum is σ = 210088342800. Its totient is φ = 35383298688.

The previous prime is 90915421699. The next prime is 90915421783. The reversal of 90915421720 is 2712451909.

It is a happy number.

It is a super-2 number, since 2×90915421720² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30713190 + ... + 30716149.

Almost surely, 2^90915421720 is an apocalyptic number.

It is an amenable number.

90915421720 is an abundant number, since it is smaller than the sum of its proper divisors (119172921080).

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

90915421720 is a wasteful number, since it uses less digits than its factorization.

90915421720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61429387 (or 61429383 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 40.

The spelling of 90915421720 in words is "ninety billion, nine hundred fifteen million, four hundred twenty-one thousand, seven hundred twenty".