90312721920 has 120 divisors (see below), whose sum is σ = 312778436256. Its totient is φ = 24083386368.

The previous prime is 90312721903. The next prime is 90312721927. The reversal of 90312721920 is 2912721309.

90312721920 is a `hidden beast` number, since 90 + 312 + 72 + 192 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90312721927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1936872 + ... + 1982951.

Almost surely, 2^90312721920 is an apocalyptic number.

90312721920 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

90312721920 is an abundant number, since it is smaller than the sum of its proper divisors (222465714336).

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

90312721920 is a wasteful number, since it uses less digits than its factorization.

90312721920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3919852 (or 3919833 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The spelling of 90312721920 in words is "ninety billion, three hundred twelve million, seven hundred twenty-one thousand, nine hundred twenty".