685040 has 20 divisors (see below), whose sum is σ = 1592904. Its totient is φ = 273984.

The previous prime is 685039. The next prime is 685051. The reversal of 685040 is 40586.

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 684997 and 685015.

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 3 ways as a sum of consecutive naturals, for example, 4202 + ... + 4361.

2⁶⁸⁵⁰⁴⁰ is an apocalyptic number.

It is an amenable number.

685040 is an abundant number, since it is smaller than the sum of its proper divisors (907864).

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

685040 is a wasteful number, since it uses less digits than its factorization.

685040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8576 (or 8570 counting only the distinct ones).

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

The square root of 685040 is about 827.6714323933. The cubic root of 685040 is about 88.1533140077.

The spelling of 685040 in words is "six hundred eighty-five thousand, forty".