685620 has 72 divisors (see below), whose sum is σ = 2247336. Its totient is φ = 168192.

The previous prime is 685613. The next prime is 685621. The reversal of 685620 is 26586.

685620 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 104976 + 580644 = 324^2 + 762^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685621) by changing a digit.

685620 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 23 ways as a sum of consecutive naturals, for example, 2194 + ... + 2486.

It is an arithmetic number, because the mean of its divisors is an integer number (31213).

2⁶⁸⁵⁶²⁰ is an apocalyptic number.

685620 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 685620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1123668).

685620 is an abundant number, since it is smaller than the sum of its proper divisors (1561716).

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

685620 is a wasteful number, since it uses less digits than its factorization.

685620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321 (or 316 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 685620 is about 828.0217388451. The cubic root of 685620 is about 88.1781857910.

The spelling of 685620 in words is "six hundred eighty-five thousand, six hundred twenty".