686918 has 16 divisors (see below), whose sum is σ = 1092960. Its totient is φ = 323136.

The previous prime is 686911. The next prime is 686947. The reversal of 686918 is 819686.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686911) 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 7 ways as a sum of consecutive naturals, for example, 4946 + ... + 5082.

It is an arithmetic number, because the mean of its divisors is an integer number (68310).

2⁶⁸⁶⁹¹⁸ is an apocalyptic number.

686918 is a deficient number, since it is larger than the sum of its proper divisors (406042).

686918 is a wasteful number, since it uses less digits than its factorization.

686918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271.

The product of its digits is 20736, while the sum is 38.

The square root of 686918 is about 828.8051640766. The cubic root of 686918 is about 88.2337963493.

The spelling of 686918 in words is "six hundred eighty-six thousand, nine hundred eighteen".