685940 has 12 divisors (see below), whose sum is σ = 1440516. Its totient is φ = 274368.

The previous prime is 685939. The next prime is 685963. The reversal of 685940 is 49586.

It can be written as a sum of positive squares in 2 ways, for example, as 481636 + 204304 = 694^2 + 452^2 .

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 junction number, because it is equal to n+sod(n) for n = 685897 and 685906.

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, 17129 + ... + 17168.

It is an arithmetic number, because the mean of its divisors is an integer number (120043).

2⁶⁸⁵⁹⁴⁰ is an apocalyptic number.

It is an amenable number.

685940 is an abundant number, since it is smaller than the sum of its proper divisors (754576).

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

685940 is a wasteful number, since it uses less digits than its factorization.

685940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34306 (or 34304 counting only the distinct ones).

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

The square root of 685940 is about 828.2149479453. The cubic root of 685940 is about 88.1919021502.

The spelling of 685940 in words is "six hundred eighty-five thousand, nine hundred forty".