18904638664 has 16 divisors (see below), whose sum is σ = 35651091420. Its totient is φ = 9397680960.

The previous prime is 18904638593. The next prime is 18904638667. The reversal of 18904638664 is 46683640981.

It can be written as a sum of positive squares in 2 ways, for example, as 18656828100 + 247810564 = 136590^2 + 15742^2 .

It is not an unprimeable number, because it can be changed into a prime (18904638667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6828327 + ... + 6831094.

Almost surely, 2^18904638664 is an apocalyptic number.

It is an amenable number.

18904638664 is a deficient number, since it is larger than the sum of its proper divisors (16746452756).

18904638664 is a wasteful number, since it uses less digits than its factorization.

18904638664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13659600 (or 13659596 counting only the distinct ones).

The product of its (nonzero) digits is 5971968, while the sum is 55.

The spelling of 18904638664 in words is "eighteen billion, nine hundred four million, six hundred thirty-eight thousand, six hundred sixty-four".