686939 has 8 divisors (see below), whose sum is σ = 755568. Its totient is φ = 619360.

The previous prime is 686911. The next prime is 686947. The reversal of 686939 is 939686.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-686939 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 686896 and 686905.

It is not an unprimeable number, because it can be changed into a prime (686969) 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 7 ways as a sum of consecutive naturals, for example, 2009 + ... + 2325.

It is an arithmetic number, because the mean of its divisors is an integer number (94446).

2⁶⁸⁶⁹³⁹ is an apocalyptic number.

686939 is a deficient number, since it is larger than the sum of its proper divisors (68629).

686939 is a wasteful number, since it uses less digits than its factorization.

686939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525.

The product of its digits is 69984, while the sum is 41.

The square root of 686939 is about 828.8178328197. The cubic root of 686939 is about 88.2346954818.

It can be divided in two parts, 68 and 6939, that added together give a palindrome (7007).

The spelling of 686939 in words is "six hundred eighty-six thousand, nine hundred thirty-nine".