685939 has 2 divisors, whose sum is σ = 685940. Its totient is φ = 685938.

The previous prime is 685907. The next prime is 685963. The reversal of 685939 is 939586.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 685939 - 2⁵ = 685907 is a prime.

It is a Chen prime.

It is a nialpdrome in base 16.

It is not a weakly prime, because it can be changed into another prime (685969) 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 as a sum of consecutive naturals, namely, 342969 + 342970.

It is an arithmetic number, because the mean of its divisors is an integer number (342970).

2⁶⁸⁵⁹³⁹ is an apocalyptic number.

685939 is a deficient number, since it is larger than the sum of its proper divisors (1).

685939 is an equidigital number, since it uses as much as digits as its factorization.

685939 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 58320, while the sum is 40.

The square root of 685939 is about 828.2143442370. The cubic root of 685939 is about 88.1918592932.

The spelling of 685939 in words is "six hundred eighty-five thousand, nine hundred thirty-nine".