18819664 has 20 divisors (see below), whose sum is σ = 37152756. Its totient is φ = 9231872.

The previous prime is 18819653. The next prime is 18819679. The reversal of 18819664 is 46691881.

It can be written as a sum of positive squares in 2 ways, for example, as 16064064 + 2755600 = 4008^2 + 1660^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18819664.

It is a congruent number.

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, 10249 + ... + 11944.

Almost surely, 2^18819664 is an apocalyptic number.

It is an amenable number.

18819664 is a deficient number, since it is larger than the sum of its proper divisors (18333092).

18819664 is a wasteful number, since it uses less digits than its factorization.

18819664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22254 (or 22248 counting only the distinct ones).

The product of its digits is 82944, while the sum is 43.

The square root of 18819664 is about 4338.1636668065. The cubic root of 18819664 is about 265.9932536401.

The spelling of 18819664 in words is "eighteen million, eight hundred nineteen thousand, six hundred sixty-four".