686686685 has 16 divisors (see below), whose sum is σ = 854136576. Its totient is φ = 529624128.

The previous prime is 686686579. The next prime is 686686687. The reversal of 686686685 is 586686686.

It is a happy number.

686686685 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-686686685 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686686687) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6062 + ... + 37551.

It is an arithmetic number, because the mean of its divisors is an integer number (53383536).

Almost surely, 2^686686685 is an apocalyptic number.

It is an amenable number.

686686685 is a deficient number, since it is larger than the sum of its proper divisors (167449891).

686686685 is a wasteful number, since it uses less digits than its factorization.

686686685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43732.

The product of its digits is 19906560, while the sum is 59.

The square root of 686686685 is about 26204.7073061311. The cubic root of 686686685 is about 882.2389119227.

Subtracting from 686686685 its reverse (586686686), we obtain a palindrome (99999999).

The spelling of 686686685 in words is "six hundred eighty-six million, six hundred eighty-six thousand, six hundred eighty-five".