686637868 has 24 divisors (see below), whose sum is σ = 1381508352. Its totient is φ = 292509264.

The previous prime is 686637857. The next prime is 686637907. The reversal of 686637868 is 868736686.

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, 68746 + ... + 78097.

It is an arithmetic number, because the mean of its divisors is an integer number (57562848).

Almost surely, 2^686637868 is an apocalyptic number.

It is an amenable number.

686637868 is an abundant number, since it is smaller than the sum of its proper divisors (694870484).

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

686637868 is a wasteful number, since it uses less digits than its factorization.

686637868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147021 (or 147019 counting only the distinct ones).

The product of its digits is 13934592, while the sum is 58.

The square root of 686637868 is about 26203.7758347914. The cubic root of 686637868 is about 882.2180051159.

The spelling of 686637868 in words is "six hundred eighty-six million, six hundred thirty-seven thousand, eight hundred sixty-eight".