18729664 has 28 divisors (see below), whose sum is σ = 37325808. Its totient is φ = 9324800.

The previous prime is 18729647. The next prime is 18729671. The reversal of 18729664 is 46692781.

It is a self number, because there is not a number n which added to its sum of digits gives 18729664.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19434 + ... + 20374.

Almost surely, 2^18729664 is an apocalyptic number.

It is an amenable number.

18729664 is a deficient number, since it is larger than the sum of its proper divisors (18596144).

18729664 is an equidigital number, since it uses as much as digits as its factorization.

18729664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1264 (or 1254 counting only the distinct ones).

The product of its digits is 145152, while the sum is 43.

The square root of 18729664 is about 4327.7781828555. The cubic root of 18729664 is about 265.5685621086.

The spelling of 18729664 in words is "eighteen million, seven hundred twenty-nine thousand, six hundred sixty-four".