685600 has 36 divisors (see below), whose sum is σ = 1675674. Its totient is φ = 273920.

The previous prime is 685591. The next prime is 685609. The reversal of 685600 is 6586.

It is an interprime number because it is at equal distance from previous prime (685591) and next prime (685609).

It can be written as a sum of positive squares in 3 ways, for example, as 633616 + 51984 = 796^2 + 228^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a nialpdrome in base 16.

It is not an unprimeable number, because it can be changed into a prime (685609) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 372 + ... + 1228.

2⁶⁸⁵⁶⁰⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 685600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (837837).

685600 is an abundant number, since it is smaller than the sum of its proper divisors (990074).

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

685600 is a wasteful number, since it uses less digits than its factorization.

685600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 877 (or 864 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 685600 is about 828.0096617794. The cubic root of 685600 is about 88.1773283768.

The spelling of 685600 in words is "six hundred eighty-five thousand, six hundred".