686312 has 24 divisors (see below), whose sum is σ = 1416450. Its totient is φ = 311520.

The previous prime is 686293. The next prime is 686317. The reversal of 686312 is 213686.

686312 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 662596 + 23716 = 814^2 + 154^2 .

It is a super-2 number, since 2×686312² = 942048322688, which contains 22 as substring.

It is a Smith number, since the sum of its digits (26) coincides with the sum of the digits of its prime factors.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (686317) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 614 + ... + 1322.

2⁶⁸⁶³¹² 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 686312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (708225).

686312 is an abundant number, since it is smaller than the sum of its proper divisors (730138).

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

686312 is a wasteful number, since it uses less digits than its factorization.

686312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 737 (or 722 counting only the distinct ones).

The product of its digits is 1728, while the sum is 26.

The square root of 686312 is about 828.4394968856. The cubic root of 686312 is about 88.2078420569.

Adding to 686312 its reverse (213686), we get a palindrome (899998).

The spelling of 686312 in words is "six hundred eighty-six thousand, three hundred twelve".