685305 has 24 divisors (see below), whose sum is σ = 1207752. Its totient is φ = 359424.

The previous prime is 685301. The next prime is 685319. The reversal of 685305 is 503586.

It can be written as a sum of positive squares in 4 ways, for example, as 24336 + 660969 = 156^2 + 813^2 .

It is not a de Polignac number, because 685305 - 2² = 685301 is a prime.

It is not an unprimeable number, because it can be changed into a prime (685301) 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, 4287 + ... + 4443.

It is an arithmetic number, because the mean of its divisors is an integer number (50323).

2⁶⁸⁵³⁰⁵ is an apocalyptic number.

It is an amenable number.

685305 is a deficient number, since it is larger than the sum of its proper divisors (522447).

685305 is a wasteful number, since it uses less digits than its factorization.

685305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 265 (or 262 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 685305 is about 827.8315045950. The cubic root of 685305 is about 88.1646795808.

It can be divided in two parts, 685 and 305, that added together give a triangular number (990 = T₄₄).

The spelling of 685305 in words is "six hundred eighty-five thousand, three hundred five".