685616 has 20 divisors (see below), whose sum is σ = 1348872. Its totient is φ = 337536.

The previous prime is 685613. The next prime is 685621. The reversal of 685616 is 616586.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a nialpdrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685613) 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, 875 + ... + 1461.

2⁶⁸⁵⁶¹⁶ is an apocalyptic number.

It is an amenable number.

685616 is a deficient number, since it is larger than the sum of its proper divisors (663256).

685616 is a wasteful number, since it uses less digits than its factorization.

685616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 668 (or 662 counting only the distinct ones).

The product of its digits is 8640, while the sum is 32.

The square root of 685616 is about 828.0193234460. The cubic root of 685616 is about 88.1780143095.

Subtracting from 685616 its sum of digits (32), we obtain a square (685584 = 828²).

The spelling of 685616 in words is "six hundred eighty-five thousand, six hundred sixteen".