686879 has 2 divisors, whose sum is σ = 686880. Its totient is φ = 686878.

The previous prime is 686863. The next prime is 686891. The reversal of 686879 is 978686.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 686879 - 2⁴ = 686863 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (686479) by changing a digit.

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

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 343439 + 343440.

It is an arithmetic number, because the mean of its divisors is an integer number (343440).

2⁶⁸⁶⁸⁷⁹ is an apocalyptic number.

686879 is a deficient number, since it is larger than the sum of its proper divisors (1).

686879 is an equidigital number, since it uses as much as digits as its factorization.

686879 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 44.

The square root of 686879 is about 828.7816358969. The cubic root of 686879 is about 88.2321264832.

The spelling of 686879 in words is "six hundred eighty-six thousand, eight hundred seventy-nine".