685307717 has 2 divisors, whose sum is σ = 685307718. Its totient is φ = 685307716.

The previous prime is 685307687. The next prime is 685307741. The reversal of 685307717 is 717703586.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 685078276 + 229441 = 26174^2 + 479^2 .

It is a cyclic number.

It is not a de Polignac number, because 685307717 - 2²² = 681113413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685307617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342653858 + 342653859.

It is an arithmetic number, because the mean of its divisors is an integer number (342653859).

Almost surely, 2^685307717 is an apocalyptic number.

It is an amenable number.

685307717 is a deficient number, since it is larger than the sum of its proper divisors (1).

685307717 is an equidigital number, since it uses as much as digits as its factorization.

685307717 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 246960, while the sum is 44.

The square root of 685307717 is about 26178.3826276567. The cubic root of 685307717 is about 881.6479609494.

The spelling of 685307717 in words is "six hundred eighty-five million, three hundred seven thousand, seven hundred seventeen".