685633942656 has 160 divisors (see below), whose sum is σ = 2197392512700. Its totient is φ = 210964248576.

The previous prime is 685633942561. The next prime is 685633942691. The reversal of 685633942656 is 656249336586.

685633942656 is a `hidden beast` number, since 6 + 8 + 563 + 3 + 9 + 4 + 2 + 65 + 6 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 684987969600 + 645973056 = 827640^2 + 25416^2 .

It is a super-2 number, since 2×685633942656² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 685633942593 and 685633942602.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2408671 + ... + 2678238.

Almost surely, 2^685633942656 is an apocalyptic number.

It is an amenable number.

685633942656 is an abundant number, since it is smaller than the sum of its proper divisors (1511758570044).

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

685633942656 is a wasteful number, since it uses less digits than its factorization.

685633942656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5086948 (or 5086927 counting only the distinct ones).

The product of its digits is 167961600, while the sum is 63.

The spelling of 685633942656 in words is "six hundred eighty-five billion, six hundred thirty-three million, nine hundred forty-two thousand, six hundred fifty-six".