685100 has 72 divisors (see below), whose sum is σ = 1749888. Its totient is φ = 230400.

The previous prime is 685099. The next prime is 685103. The reversal of 685100 is 1586.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is not an unprimeable number, because it can be changed into a prime (685103) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22085 + ... + 22115.

It is an arithmetic number, because the mean of its divisors is an integer number (24304).

2⁶⁸⁵¹⁰⁰ 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 685100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (874944).

685100 is an abundant number, since it is smaller than the sum of its proper divisors (1064788).

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

685100 is a wasteful number, since it uses less digits than its factorization.

685100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75 (or 68 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 685100 is about 827.7076778670. The cubic root of 685100 is about 88.1558876017.

Adding to 685100 its reverse (1586), we get a palindrome (686686).

The spelling of 685100 in words is "six hundred eighty-five thousand, one hundred".