18715664 has 40 divisors (see below), whose sum is σ = 40494432. Its totient is φ = 8305920.

The previous prime is 18715663. The next prime is 18715679. The reversal of 18715664 is 46651781.

It is not an unprimeable number, because it can be changed into a prime (18715663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6332 + ... + 8804.

Almost surely, 2^18715664 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 18715664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20247216).

18715664 is an abundant number, since it is smaller than the sum of its proper divisors (21778768).

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

18715664 is a wasteful number, since it uses less digits than its factorization.

18715664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2535 (or 2529 counting only the distinct ones).

The product of its digits is 40320, while the sum is 38.

The square root of 18715664 is about 4326.1604223607. The cubic root of 18715664 is about 265.5023767850.

It can be divided in two parts, 187 and 15664, that added together give a palindrome (15851).

The spelling of 18715664 in words is "eighteen million, seven hundred fifteen thousand, six hundred sixty-four".