686864665922 has 18 divisors (see below), whose sum is σ = 1037432654937. Its totient is φ = 341070042000.

The previous prime is 686864665919. The next prime is 686864665931. The reversal of 686864665922 is 229566468686.

686864665922 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 675011771281 + 11852894641 = 821591^2 + 108871^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=586031.

It is a super-2 number, since 2×686864665922² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 176979422 + ... + 176983302.

Almost surely, 2^686864665922 is an apocalyptic number.

686864665922 is a deficient number, since it is larger than the sum of its proper divisors (350567989015).

686864665922 is an frugal number, since it uses more digits than its factorization.

686864665922 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8066 (or 4034 counting only the distinct ones).

The product of its digits is 358318080, while the sum is 68.

The spelling of 686864665922 in words is "six hundred eighty-six billion, eight hundred sixty-four million, six hundred sixty-five thousand, nine hundred twenty-two".