18664666 has 16 divisors (see below), whose sum is σ = 29576448. Its totient is φ = 8820000.

The previous prime is 18664651. The next prime is 18664673. The reversal of 18664666 is 66646681.

It is a Harshad number since it is a multiple of its sum of digits (43).

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 7 ways as a sum of consecutive naturals, for example, 835 + ... + 6166.

It is an arithmetic number, because the mean of its divisors is an integer number (1848528).

Almost surely, 2^18664666 is an apocalyptic number.

18664666 is a deficient number, since it is larger than the sum of its proper divisors (10911782).

18664666 is a wasteful number, since it uses less digits than its factorization.

18664666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7077.

The product of its digits is 248832, while the sum is 43.

The square root of 18664666 is about 4320.2622605578. The cubic root of 18664666 is about 265.2610030841.

The spelling of 18664666 in words is "eighteen million, six hundred sixty-four thousand, six hundred sixty-six".