18668686686 has 32 divisors (see below), whose sum is σ = 40215211008. Its totient is φ = 5743392480.

The previous prime is 18668686657. The next prime is 18668686739. The reversal of 18668686686 is 68668686681.

It is a self number, because there is not a number n which added to its sum of digits gives 18668686686.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 757815 + ... + 782061.

It is an arithmetic number, because the mean of its divisors is an integer number (1256725344).

Almost surely, 2^18668686686 is an apocalyptic number.

18668686686 is an abundant number, since it is smaller than the sum of its proper divisors (21546524322).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18668686686 is a wasteful number, since it uses less digits than its factorization.

18668686686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34136.

The product of its digits is 191102976, while the sum is 69.

It can be divided in two parts, 186686 and 86686, that added together give a palindrome (273372).

The spelling of 18668686686 in words is "eighteen billion, six hundred sixty-eight million, six hundred eighty-six thousand, six hundred eighty-six".