685400 has 48 divisors (see below), whose sum is σ = 1674000. Its totient is φ = 260480.

The previous prime is 685393. The next prime is 685417. The reversal of 685400 is 4586.

685400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a congruent number.

It is an unprimeable number.

685400 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 11 ways as a sum of consecutive naturals, for example, 4526 + ... + 4674.

It is an arithmetic number, because the mean of its divisors is an integer number (34875).

2⁶⁸⁵⁴⁰⁰ 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 685400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (837000).

685400 is an abundant number, since it is smaller than the sum of its proper divisors (988600).

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

685400 is a wasteful number, since it uses less digits than its factorization.

685400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188 (or 179 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 685400 is about 827.8888814328. Note that the first 5 decimals coincide. The cubic root of 685400 is about 88.1687533181.

Adding to 685400 its reverse (4586), we get a palindrome (689986).

The spelling of 685400 in words is "six hundred eighty-five thousand, four hundred".