684857656 has 16 divisors (see below), whose sum is σ = 1467552240. Its totient is φ = 293510400.

The previous prime is 684857647. The next prime is 684857659. The reversal of 684857656 is 656758486.

It is a junction number, because it is equal to n+sod(n) for n = 684857597 and 684857606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684857659) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6114745 + ... + 6114856.

It is an arithmetic number, because the mean of its divisors is an integer number (91722015).

Almost surely, 2^684857656 is an apocalyptic number.

It is an amenable number.

684857656 is an abundant number, since it is smaller than the sum of its proper divisors (782694584).

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

684857656 is a wasteful number, since it uses less digits than its factorization.

684857656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12229614 (or 12229610 counting only the distinct ones).

The product of its digits is 9676800, while the sum is 55.

The square root of 684857656 is about 26169.7851729815. The cubic root of 684857656 is about 881.4549176167.

The spelling of 684857656 in words is "six hundred eighty-four million, eight hundred fifty-seven thousand, six hundred fifty-six".