18664665 has 16 divisors (see below), whose sum is σ = 29966976. Its totient is φ = 9920000.

The previous prime is 18664651. The next prime is 18664673. The reversal of 18664665 is 56646681.

It is not a de Polignac number, because 18664665 - 2⁴ = 18664649 is a prime.

Its product of digits (207360) is a multiple of the sum of its prime divisors (4320).

It is an unprimeable number.

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, 2665 + ... + 6665.

It is an arithmetic number, because the mean of its divisors is an integer number (1872936).

Almost surely, 2^18664665 is an apocalyptic number.

18664665 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

18664665 is a deficient number, since it is larger than the sum of its proper divisors (11302311).

18664665 is a wasteful number, since it uses less digits than its factorization.

18664665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4320.

The product of its digits is 207360, while the sum is 42.

The square root of 18664665 is about 4320.2621448241. The cubic root of 18664665 is about 265.2609983468.

The spelling of 18664665 in words is "eighteen million, six hundred sixty-four thousand, six hundred sixty-five".