685778653663 has 2 divisors, whose sum is σ = 685778653664. Its totient is φ = 685778653662.

The previous prime is 685778653657. The next prime is 685778653711. The reversal of 685778653663 is 366356877586.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 685778653663 - 2⁹ = 685778653151 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 685778653592 and 685778653601.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685778653613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342889326831 + 342889326832.

It is an arithmetic number, because the mean of its divisors is an integer number (342889326832).

Almost surely, 2^685778653663 is an apocalyptic number.

685778653663 is a deficient number, since it is larger than the sum of its proper divisors (1).

685778653663 is an equidigital number, since it uses as much as digits as its factorization.

685778653663 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 914457600, while the sum is 70.

The spelling of 685778653663 in words is "six hundred eighty-five billion, seven hundred seventy-eight million, six hundred fifty-three thousand, six hundred sixty-three".