685688 has 8 divisors (see below), whose sum is σ = 1285680. Its totient is φ = 342840.

The previous prime is 685679. The next prime is 685697. The reversal of 685688 is 886586.

It is an interprime number because it is at equal distance from previous prime (685679) and next prime (685697).

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 685688.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42848 + ... + 42863.

It is an arithmetic number, because the mean of its divisors is an integer number (160710).

2⁶⁸⁵⁶⁸⁸ is an apocalyptic number.

It is an amenable number.

685688 is a deficient number, since it is larger than the sum of its proper divisors (599992).

685688 is a wasteful number, since it uses less digits than its factorization.

685688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85717 (or 85713 counting only the distinct ones).

The product of its digits is 92160, while the sum is 41.

The square root of 685688 is about 828.0627995509. The cubic root of 685688 is about 88.1811008744.

The spelling of 685688 in words is "six hundred eighty-five thousand, six hundred eighty-eight".