686980 has 36 divisors (see below), whose sum is σ = 1680588. Its totient is φ = 235200.

The previous prime is 686977. The next prime is 686989. The reversal of 686980 is 89686.

686980 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 2 ways, for example, as 432964 + 254016 = 658^2 + 504^2 .

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (686989) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 630 + ... + 1330.

It is an arithmetic number, because the mean of its divisors is an integer number (46683).

2⁶⁸⁶⁹⁸⁰ 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 686980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (840294).

686980 is an abundant number, since it is smaller than the sum of its proper divisors (993608).

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

686980 is a wasteful number, since it uses less digits than its factorization.

686980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 724 (or 715 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 686980 is about 828.8425664745. The cubic root of 686980 is about 88.2364508781.

The spelling of 686980 in words is "six hundred eighty-six thousand, nine hundred eighty".