18661408 has 12 divisors (see below), whose sum is σ = 36739710. Its totient is φ = 9330688.

The previous prime is 18661387. The next prime is 18661417. The reversal of 18661408 is 80416681.

It can be written as a sum of positive squares in only one way, i.e., 14047504 + 4613904 = 3748^2 + 2148^2 .

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

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, 291553 + ... + 291616.

Almost surely, 2^18661408 is an apocalyptic number.

It is an amenable number.

18661408 is a deficient number, since it is larger than the sum of its proper divisors (18078302).

18661408 is an equidigital number, since it uses as much as digits as its factorization.

18661408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 583179 (or 583171 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 34.

The square root of 18661408 is about 4319.8851836594. The cubic root of 18661408 is about 265.2455680256.

The spelling of 18661408 in words is "eighteen million, six hundred sixty-one thousand, four hundred eight".