16623665 has 16 divisors (see below), whose sum is σ = 20570112. Its totient is φ = 12890304.

The previous prime is 16623653. The next prime is 16623683. The reversal of 16623665 is 56632661.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16623665 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29567 + ... + 30123.

It is an arithmetic number, because the mean of its divisors is an integer number (1285632).

Almost surely, 2^16623665 is an apocalyptic number.

It is an amenable number.

16623665 is a deficient number, since it is larger than the sum of its proper divisors (3946447).

16623665 is a wasteful number, since it uses less digits than its factorization.

16623665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 736.

The product of its digits is 38880, while the sum is 35.

The square root of 16623665 is about 4077.2128960848. The cubic root of 16623665 is about 255.2166043726.

The spelling of 16623665 in words is "sixteen million, six hundred twenty-three thousand, six hundred sixty-five".