686867 has 4 divisors (see below), whose sum is σ = 709056. Its totient is φ = 664680.

The previous prime is 686863. The next prime is 686879. The reversal of 686867 is 768686.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 768686 = 2 ⋅384343.

It is a cyclic number.

It is not a de Polignac number, because 686867 - 2² = 686863 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 686867.

It is not an unprimeable number, because it can be changed into a prime (686863) 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 3 ways as a sum of consecutive naturals, for example, 11048 + ... + 11109.

It is an arithmetic number, because the mean of its divisors is an integer number (177264).

2⁶⁸⁶⁸⁶⁷ is an apocalyptic number.

686867 is a deficient number, since it is larger than the sum of its proper divisors (22189).

686867 is a wasteful number, since it uses less digits than its factorization.

686867 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22188.

The product of its digits is 96768, while the sum is 41.

The square root of 686867 is about 828.7743963227. The cubic root of 686867 is about 88.2316126656.

The spelling of 686867 in words is "six hundred eighty-six thousand, eight hundred sixty-seven".