685590 has 16 divisors (see below), whose sum is σ = 1645488. Its totient is φ = 182816.

The previous prime is 685547. The next prime is 685591. The reversal of 685590 is 95586.

685590 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685591) by changing a digit.

685590 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11397 + ... + 11456.

It is an arithmetic number, because the mean of its divisors is an integer number (102843).

2⁶⁸⁵⁵⁹⁰ is an apocalyptic number.

685590 is an abundant number, since it is smaller than the sum of its proper divisors (959898).

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

685590 is a wasteful number, since it uses less digits than its factorization.

685590 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22863.

The product of its (nonzero) digits is 10800, while the sum is 33.

The square root of 685590 is about 828.0036231805. The cubic root of 685590 is about 88.1768996635.

It can be divided in two parts, 685 and 590, that added together give a triangular number (1275 = T₅₀).

The spelling of 685590 in words is "six hundred eighty-five thousand, five hundred ninety".