18939926665 has 16 divisors (see below), whose sum is σ = 24796759680. Its totient is φ = 13773006720.

The previous prime is 18939926659. The next prime is 18939926711. The reversal of 18939926665 is 56662993981.

It is not a de Polignac number, because 18939926665 - 2³ = 18939926657 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18939926597 and 18939926606.

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, 976492 + ... + 995698.

It is an arithmetic number, because the mean of its divisors is an integer number (1549797480).

Almost surely, 2^18939926665 is an apocalyptic number.

It is an amenable number.

18939926665 is a deficient number, since it is larger than the sum of its proper divisors (5856833015).

18939926665 is a wasteful number, since it uses less digits than its factorization.

18939926665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37152.

The product of its digits is 37791360, while the sum is 64.

The spelling of 18939926665 in words is "eighteen billion, nine hundred thirty-nine million, nine hundred twenty-six thousand, six hundred sixty-five".