18315728 has 40 divisors (see below), whose sum is σ = 37604736. Its totient is φ = 8624000.

The previous prime is 18315727. The next prime is 18315743. The reversal of 18315728 is 82751381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18315727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25778 + ... + 26478.

Almost surely, 2^18315728 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 18315728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18802368).

18315728 is an abundant number, since it is smaller than the sum of its proper divisors (19289008).

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

18315728 is a wasteful number, since it uses less digits than its factorization.

18315728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 803 (or 797 counting only the distinct ones).

The product of its digits is 13440, while the sum is 35.

The square root of 18315728 is about 4279.6878390836. The cubic root of 18315728 is about 263.5975656090.

The spelling of 18315728 in words is "eighteen million, three hundred fifteen thousand, seven hundred twenty-eight".