16644323645 has 16 divisors (see below), whose sum is σ = 20638888320. Its totient is φ = 12876076224.

The previous prime is 16644323593. The next prime is 16644323669. The reversal of 16644323645 is 54632344661.

It is a cyclic number.

It is not a de Polignac number, because 16644323645 - 2⁸ = 16644323389 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 16644323596 and 16644323605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 245825 + ... + 306134.

It is an arithmetic number, because the mean of its divisors is an integer number (1289930520).

Almost surely, 2^16644323645 is an apocalyptic number.

It is an amenable number.

16644323645 is a deficient number, since it is larger than the sum of its proper divisors (3994564675).

16644323645 is a wasteful number, since it uses less digits than its factorization.

16644323645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 552164.

The product of its digits is 1244160, while the sum is 44.

The spelling of 16644323645 in words is "sixteen billion, six hundred forty-four million, three hundred twenty-three thousand, six hundred forty-five".