685503859949 has 2 divisors, whose sum is σ = 685503859950. Its totient is φ = 685503859948.

The previous prime is 685503859921. The next prime is 685503859967. The reversal of 685503859949 is 949958305586.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 656898903049 + 28604956900 = 810493^2 + 169130^2 .

It is a cyclic number.

It is not a de Polignac number, because 685503859949 - 2⁸ = 685503859693 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685503859919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342751929974 + 342751929975.

It is an arithmetic number, because the mean of its divisors is an integer number (342751929975).

Almost surely, 2^685503859949 is an apocalyptic number.

It is an amenable number.

685503859949 is a deficient number, since it is larger than the sum of its proper divisors (1).

685503859949 is an equidigital number, since it uses as much as digits as its factorization.

685503859949 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 419904000, while the sum is 71.

The spelling of 685503859949 in words is "six hundred eighty-five billion, five hundred three million, eight hundred fifty-nine thousand, nine hundred forty-nine".