685550 has 12 divisors (see below), whose sum is σ = 1275216. Its totient is φ = 274200.

The previous prime is 685547. The next prime is 685591. The reversal of 685550 is 55586.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6806 + ... + 6905.

It is an arithmetic number, because the mean of its divisors is an integer number (106268).

2⁶⁸⁵⁵⁵⁰ is an apocalyptic number.

685550 is a deficient number, since it is larger than the sum of its proper divisors (589666).

685550 is a wasteful number, since it uses less digits than its factorization.

685550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13723 (or 13718 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 29.

The square root of 685550 is about 827.9794683445. The cubic root of 685550 is about 88.1751847685.

The spelling of 685550 in words is "six hundred eighty-five thousand, five hundred fifty".