18728664 has 64 divisors (see below), whose sum is σ = 49248000. Its totient is φ = 5927040.

The previous prime is 18728653. The next prime is 18728669. The reversal of 18728664 is 46682781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18728669) 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 15 ways as a sum of consecutive naturals, for example, 49227 + ... + 49605.

It is an arithmetic number, because the mean of its divisors is an integer number (769500).

Almost surely, 2^18728664 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 18728664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24624000).

18728664 is an abundant number, since it is smaller than the sum of its proper divisors (30519336).

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

18728664 is a wasteful number, since it uses less digits than its factorization.

18728664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 488 (or 484 counting only the distinct ones).

The product of its digits is 129024, while the sum is 42.

The square root of 18728664 is about 4327.6626485899. The cubic root of 18728664 is about 265.5638356794.

The spelling of 18728664 in words is "eighteen million, seven hundred twenty-eight thousand, six hundred sixty-four".