686647564164 has 27 divisors (see below), whose sum is σ = 1735705021687. Its totient is φ = 228880864104.

The previous prime is 686647564121. The next prime is 686647564171. The reversal of 686647564164 is 461465746686.

It is a happy number.

The square root of 686647564164 is 828642.

It is a perfect power (a square), and thus also a powerful number.

686647564164 is a `hidden beast` number, since 6 + 8 + 6 + 6 + 4 + 7 + 564 + 1 + 64 = 666.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 4902799 + ... + 5040905.

Almost surely, 2^686647564164 is an apocalyptic number.

686647564164 is the 828642-nd square number.

It is an amenable number.

686647564164 is an abundant number, since it is smaller than the sum of its proper divisors (1049057457523).

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

686647564164 is an frugal number, since it uses more digits than its factorization.

686647564164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276224 (or 138112 counting only the distinct ones).

The product of its digits is 139345920, while the sum is 63.

The spelling of 686647564164 in words is "six hundred eighty-six billion, six hundred forty-seven million, five hundred sixty-four thousand, one hundred sixty-four".