18993920 has 144 divisors (see below), whose sum is σ = 52980480. Its totient is φ = 6451200.

The previous prime is 18993911. The next prime is 18993937. The reversal of 18993920 is 2939981.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors.

It is a congruent number.

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, 267485 + ... + 267555.

It is an arithmetic number, because the mean of its divisors is an integer number (367920).

Almost surely, 2^18993920 is an apocalyptic number.

18993920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18993920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26490240).

18993920 is an abundant number, since it is smaller than the sum of its proper divisors (33986560).

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

18993920 is a wasteful number, since it uses less digits than its factorization.

18993920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122 (or 108 counting only the distinct ones).

The product of its (nonzero) digits is 34992, while the sum is 41.

The square root of 18993920 is about 4358.2014639069. The cubic root of 18993920 is about 266.8116988847.

The spelling of 18993920 in words is "eighteen million, nine hundred ninety-three thousand, nine hundred twenty".