18405664 has 12 divisors (see below), whose sum is σ = 36236214. Its totient is φ = 9202816.

The previous prime is 18405649. The next prime is 18405671. The reversal of 18405664 is 46650481.

It can be written as a sum of positive squares in only one way, i.e., 18147600 + 258064 = 4260^2 + 508^2 .

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 polite number, since it can be written as a sum of consecutive naturals, namely, 287557 + ... + 287620.

Almost surely, 2^18405664 is an apocalyptic number.

It is an amenable number.

18405664 is a deficient number, since it is larger than the sum of its proper divisors (17830550).

18405664 is an equidigital number, since it uses as much as digits as its factorization.

18405664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 575187 (or 575179 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 34.

The square root of 18405664 is about 4290.1822805098. The cubic root of 18405664 is about 264.0283104014.

The spelling of 18405664 in words is "eighteen million, four hundred five thousand, six hundred sixty-four".