686240 has 24 divisors (see below), whose sum is σ = 1621620. Its totient is φ = 274432.

The previous prime is 686209. The next prime is 686267. The reversal of 686240 is 42686.

It can be written as a sum of positive squares in 2 ways, for example, as 659344 + 26896 = 812^2 + 164^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1985 + ... + 2304.

2⁶⁸⁶²⁴⁰ is an apocalyptic number.

It is an amenable number.

686240 is an abundant number, since it is smaller than the sum of its proper divisors (935380).

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

686240 is a wasteful number, since it uses less digits than its factorization.

686240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4304 (or 4296 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 686240 is about 828.3960405507. The cubic root of 686240 is about 88.2047573632.

The spelling of 686240 in words is "six hundred eighty-six thousand, two hundred forty".