18320144 has 20 divisors (see below), whose sum is σ = 37039296. Its totient is φ = 8761632.

The previous prime is 18320117. The next prime is 18320189. The reversal of 18320144 is 44102381.

It is a Harshad number since it is a multiple of its sum of digits (23).

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, 24524 + ... + 25259.

Almost surely, 2^18320144 is an apocalyptic number.

It is an amenable number.

18320144 is an abundant number, since it is smaller than the sum of its proper divisors (18719152).

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

18320144 is a wasteful number, since it uses less digits than its factorization.

18320144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49814 (or 49808 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 18320144 is about 4280.2037334688. The cubic root of 18320144 is about 263.6187487384.

The spelling of 18320144 in words is "eighteen million, three hundred twenty thousand, one hundred forty-four".