685717 has 2 divisors, whose sum is σ = 685718. Its totient is φ = 685716.

The previous prime is 685697. The next prime is 685723. The reversal of 685717 is 717586.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 461041 + 224676 = 679^2 + 474^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-685717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685747) 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 as a sum of consecutive naturals, namely, 342858 + 342859.

It is an arithmetic number, because the mean of its divisors is an integer number (342859).

2⁶⁸⁵⁷¹⁷ is an apocalyptic number.

It is an amenable number.

685717 is a deficient number, since it is larger than the sum of its proper divisors (1).

685717 is an equidigital number, since it uses as much as digits as its factorization.

685717 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11760, while the sum is 34.

The square root of 685717 is about 828.0803101149. The cubic root of 685717 is about 88.1823440131.

The spelling of 685717 in words is "six hundred eighty-five thousand, seven hundred seventeen".