686686689 has 24 divisors (see below), whose sum is σ = 1114626240. Its totient is φ = 404201952.

The previous prime is 686686687. The next prime is 686686697. The reversal of 686686689 is 986686686.

It is not a de Polignac number, because 686686689 - 2¹ = 686686687 is a prime.

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

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 124899 + ... + 130280.

It is an arithmetic number, because the mean of its divisors is an integer number (46442760).

Almost surely, 2^686686689 is an apocalyptic number.

686686689 is a gapful number since it is divisible by the number (69) formed by its first and last digit.

It is an amenable number.

686686689 is a deficient number, since it is larger than the sum of its proper divisors (427939551).

686686689 is a wasteful number, since it uses less digits than its factorization.

686686689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255221 (or 255218 counting only the distinct ones).

The product of its digits is 35831808, while the sum is 63.

The square root of 686686689 is about 26204.7073824533. The cubic root of 686686689 is about 882.2389136357.

It can be divided in two parts, 68668 and 6689, that added together give a palindrome (75357).

The spelling of 686686689 in words is "six hundred eighty-six million, six hundred eighty-six thousand, six hundred eighty-nine".