684656 has 20 divisors (see below), whose sum is σ = 1516272. Its totient is φ = 293376.

The previous prime is 684647. The next prime is 684683. The reversal of 684656 is 656486.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2945 + ... + 3168.

2⁶⁸⁴⁶⁵⁶ is an apocalyptic number.

It is an amenable number.

684656 is an abundant number, since it is smaller than the sum of its proper divisors (831616).

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

684656 is a wasteful number, since it uses less digits than its factorization.

684656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6128 (or 6122 counting only the distinct ones).

The product of its digits is 34560, while the sum is 35.

The square root of 684656 is about 827.4394237647. The cubic root of 684656 is about 88.1368394468.

The spelling of 684656 in words is "six hundred eighty-four thousand, six hundred fifty-six".