18739728 has 80 divisors (see below), whose sum is σ = 61484160. Its totient is φ = 5353344.

The previous prime is 18739727. The next prime is 18739741. The reversal of 18739728 is 82793781.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (18739727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 75 + ... + 6122.

It is an arithmetic number, because the mean of its divisors is an integer number (768552).

Almost surely, 2^18739728 is an apocalyptic number.

18739728 is a gapful number since it is divisible by the number (18) 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 18739728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30742080).

18739728 is an abundant number, since it is smaller than the sum of its proper divisors (42744432).

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

18739728 is a wasteful number, since it uses less digits than its factorization.

18739728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6221 (or 6209 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 18739728 is about 4328.9407480353. The cubic root of 18739728 is about 265.6161195278.

The spelling of 18739728 in words is "eighteen million, seven hundred thirty-nine thousand, seven hundred twenty-eight".