16644665 has 16 divisors (see below), whose sum is σ = 21141120. Its totient is φ = 12545280.

The previous prime is 16644629. The next prime is 16644671. The reversal of 16644665 is 56644661.

It is a de Polignac number, because none of the positive numbers 2^k-16644665 is a prime.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 22532 + ... + 23258.

It is an arithmetic number, because the mean of its divisors is an integer number (1321320).

Almost surely, 2^16644665 is an apocalyptic number.

It is an amenable number.

16644665 is a deficient number, since it is larger than the sum of its proper divisors (4496455).

16644665 is a wasteful number, since it uses less digits than its factorization.

16644665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 992.

The product of its digits is 103680, while the sum is 38.

The square root of 16644665 is about 4079.7873719105. The cubic root of 16644665 is about 255.3240274036.

The spelling of 16644665 in words is "sixteen million, six hundred forty-four thousand, six hundred sixty-five".