18391920090 has 32 divisors (see below), whose sum is σ = 44799428160. Its totient is φ = 4831309824.

The previous prime is 18391920073. The next prime is 18391920109. The reversal of 18391920090 is 9002919381.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4573095 + ... + 4577114.

It is an arithmetic number, because the mean of its divisors is an integer number (1399982130).

Almost surely, 2^18391920090 is an apocalyptic number.

18391920090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18391920090 is an abundant number, since it is smaller than the sum of its proper divisors (26407508070).

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

18391920090 is a wasteful number, since it uses less digits than its factorization.

18391920090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9150286.

The product of its (nonzero) digits is 34992, while the sum is 42.

The spelling of 18391920090 in words is "eighteen billion, three hundred ninety-one million, nine hundred twenty thousand, ninety".