685566 has 24 divisors (see below), whose sum is σ = 1697904. Its totient is φ = 195840.

The previous prime is 685547. The next prime is 685591. The reversal of 685566 is 665586.

It is a self number, because there is not a number n which added to its sum of digits gives 685566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2595 + ... + 2846.

It is an arithmetic number, because the mean of its divisors is an integer number (70746).

2⁶⁸⁵⁵⁶⁶ is an apocalyptic number.

685566 is an abundant number, since it is smaller than the sum of its proper divisors (1012338).

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

685566 is a wasteful number, since it uses less digits than its factorization.

685566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5456 (or 5453 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 685566 is about 827.9891303634. The cubic root of 685566 is about 88.1758707345.

The spelling of 685566 in words is "six hundred eighty-five thousand, five hundred sixty-six".