18945664 has 16 divisors (see below), whose sum is σ = 37743570. Its totient is φ = 9472768.

The previous prime is 18945659. The next prime is 18945683. The reversal of 18945664 is 46654981.

It can be written as a sum of positive squares in only one way, i.e., 18318400 + 627264 = 4280^2 + 792^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is a self number, because there is not a number n which added to its sum of digits gives 18945664.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 73879 + ... + 74134.

Almost surely, 2^18945664 is an apocalyptic number.

It is an amenable number.

18945664 is a deficient number, since it is larger than the sum of its proper divisors (18797906).

18945664 is an equidigital number, since it uses as much as digits as its factorization.

18945664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148027 (or 148015 counting only the distinct ones).

The product of its digits is 207360, while the sum is 43.

The square root of 18945664 is about 4352.6617143996. The cubic root of 18945664 is about 266.5855531075.

The spelling of 18945664 in words is "eighteen million, nine hundred forty-five thousand, six hundred sixty-four".