685404 has 36 divisors (see below), whose sum is σ = 1761760. Its totient is φ = 224640.

The previous prime is 685393. The next prime is 685417. The reversal of 685404 is 404586.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2724 + ... + 2964.

2⁶⁸⁵⁴⁰⁴ 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 685404, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (880880).

685404 is an abundant number, since it is smaller than the sum of its proper divisors (1076356).

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

685404 is a wasteful number, since it uses less digits than its factorization.

685404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330 (or 325 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 27.

The square root of 685404 is about 827.8912972124. The cubic root of 685404 is about 88.1689248356.

It can be divided in two parts, 685 and 404, that added together give a square (1089 = 33²).

The spelling of 685404 in words is "six hundred eighty-five thousand, four hundred four".