686979 has 12 divisors (see below), whose sum is σ = 1019616. Its totient is φ = 445392.

The previous prime is 686977. The next prime is 686989. The reversal of 686979 is 979686.

It is not a de Polignac number, because 686979 - 2¹ = 686977 is a prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 686979.

It is not an unprimeable number, because it can be changed into a prime (686971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 699 + ... + 1364.

It is an arithmetic number, because the mean of its divisors is an integer number (84968).

2⁶⁸⁶⁹⁷⁹ is an apocalyptic number.

686979 is a deficient number, since it is larger than the sum of its proper divisors (332637).

686979 is a wasteful number, since it uses less digits than its factorization.

686979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2106 (or 2103 counting only the distinct ones).

The product of its digits is 163296, while the sum is 45.

The square root of 686979 is about 828.8419632234. The cubic root of 686979 is about 88.2364080644.

The spelling of 686979 in words is "six hundred eighty-six thousand, nine hundred seventy-nine".