18909320 has 32 divisors (see below), whose sum is σ = 42946200. Its totient is φ = 7492608.

The previous prime is 18909311. The next prime is 18909337. The reversal of 18909320 is 2390981.

It can be written as a sum of positive squares in 4 ways, for example, as 11035684 + 7873636 = 3322^2 + 2806^2 .

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, 2192 + ... + 6528.

Almost surely, 2^18909320 is an apocalyptic number.

18909320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18909320 is an abundant number, since it is smaller than the sum of its proper divisors (24036880).

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

18909320 is a wasteful number, since it uses less digits than its factorization.

18909320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4457 (or 4453 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 18909320 is about 4348.4847935804. The cubic root of 18909320 is about 266.4149778002.

The spelling of 18909320 in words is "eighteen million, nine hundred nine thousand, three hundred twenty".