686320 has 40 divisors (see below), whose sum is σ = 1669536. Its totient is φ = 261888.

The previous prime is 686317. The next prime is 686321. The reversal of 686320 is 23686.

686320 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (25) coincides with the sum of the digits of its distinct prime factors.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1654 + ... + 2026.

2⁶⁸⁶³²⁰ 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 686320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (834768).

686320 is an abundant number, since it is smaller than the sum of its proper divisors (983216).

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

686320 is a wasteful number, since it uses less digits than its factorization.

686320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 409 (or 403 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 686320 is about 828.4443252265. Note that the first 3 decimals coincide. The cubic root of 686320 is about 88.2081847873.

The spelling of 686320 in words is "six hundred eighty-six thousand, three hundred twenty".