685778653613 has 2 divisors, whose sum is σ = 685778653614. Its totient is φ = 685778653612.

The previous prime is 685778653607. The next prime is 685778653627. The reversal of 685778653613 is 316356877586.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 684900242569 + 878411044 = 827587^2 + 29638^2 .

It is a cyclic number.

It is not a de Polignac number, because 685778653613 - 2⁴ = 685778653597 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 685778653613.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685778653633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342889326806 + 342889326807.

It is an arithmetic number, because the mean of its divisors is an integer number (342889326807).

Almost surely, 2^685778653613 is an apocalyptic number.

It is an amenable number.

685778653613 is a deficient number, since it is larger than the sum of its proper divisors (1).

685778653613 is an equidigital number, since it uses as much as digits as its factorization.

685778653613 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 152409600, while the sum is 65.

The spelling of 685778653613 in words is "six hundred eighty-five billion, seven hundred seventy-eight million, six hundred fifty-three thousand, six hundred thirteen".