6686578663656 has 32 divisors (see below), whose sum is σ = 17596259642400. Its totient is φ = 2111551156800.

The previous prime is 6686578663631. The next prime is 6686578663673. The reversal of 6686578663656 is 6563668756866.

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 7 ways as a sum of consecutive naturals, for example, 7331774395 + ... + 7331775306.

It is an arithmetic number, because the mean of its divisors is an integer number (549883113825).

Almost surely, 2^{6686578663656} is an apocalyptic number.

It is an amenable number.

6686578663656 is an abundant number, since it is smaller than the sum of its proper divisors (10909680978744).

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

6686578663656 is a wasteful number, since it uses less digits than its factorization.

6686578663656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14663549729 (or 14663549725 counting only the distinct ones).

The product of its digits is 9405849600, while the sum is 78.

The spelling of 6686578663656 in words is "six trillion, six hundred eighty-six billion, five hundred seventy-eight million, six hundred sixty-three thousand, six hundred fifty-six".