685660319 has 2 divisors, whose sum is σ = 685660320. Its totient is φ = 685660318.

The previous prime is 685660307. The next prime is 685660403. The reversal of 685660319 is 913066586.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-685660319 is a prime.

It is a super-2 number, since 2×685660319² = 940260146102363522, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 685660319.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685660219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342830159 + 342830160.

It is an arithmetic number, because the mean of its divisors is an integer number (342830160).

Almost surely, 2^685660319 is an apocalyptic number.

685660319 is a deficient number, since it is larger than the sum of its proper divisors (1).

685660319 is an equidigital number, since it uses as much as digits as its factorization.

685660319 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 233280, while the sum is 44.

The square root of 685660319 is about 26185.1163640722. The cubic root of 685660319 is about 881.7991424434.

The spelling of 685660319 in words is "six hundred eighty-five million, six hundred sixty thousand, three hundred nineteen".