18943728 has 80 divisors (see below), whose sum is σ = 52377600. Its totient is φ = 5886720.

The previous prime is 18943669. The next prime is 18943747. The reversal of 18943728 is 82734981.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

Its product of digits (96768) is a multiple of the sum of its prime divisors (504).

It is a self number, because there is not a number n which added to its sum of digits gives 18943728.

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, 42933 + ... + 43371.

It is an arithmetic number, because the mean of its divisors is an integer number (654720).

Almost surely, 2^18943728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18943728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26188800).

18943728 is an abundant number, since it is smaller than the sum of its proper divisors (33433872).

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

18943728 is a wasteful number, since it uses less digits than its factorization.

18943728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 510 (or 504 counting only the distinct ones).

The product of its digits is 96768, while the sum is 42.

The square root of 18943728 is about 4352.4393160617. The cubic root of 18943728 is about 266.5764722749.

The spelling of 18943728 in words is "eighteen million, nine hundred forty-three thousand, seven hundred twenty-eight".