686686815688 has 32 divisors (see below), whose sum is σ = 1355357203200. Its totient is φ = 325259675712.

The previous prime is 686686815673. The next prime is 686686815697. The reversal of 686686815688 is 886518686686.

It is a Harshad number since it is a multiple of its sum of digits (76).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4471881 + ... + 4622887.

It is an arithmetic number, because the mean of its divisors is an integer number (42354912600).

Almost surely, 2^686686815688 is an apocalyptic number.

It is an amenable number.

686686815688 is a deficient number, since it is larger than the sum of its proper divisors (668670387512).

686686815688 is a wasteful number, since it uses less digits than its factorization.

686686815688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 180949 (or 180945 counting only the distinct ones).

The product of its digits is 1274019840, while the sum is 76.

It can be divided in two parts, 68668681 and 5688, that added together give a square (68674369 = 8287²).

The spelling of 686686815688 in words is "six hundred eighty-six billion, six hundred eighty-six million, eight hundred fifteen thousand, six hundred eighty-eight".