685681225673 has 2 divisors, whose sum is σ = 685681225674. Its totient is φ = 685681225672.

The previous prime is 685681225661. The next prime is 685681225709. The reversal of 685681225673 is 376522186586.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 509677482889 + 176003742784 = 713917^2 + 419528^2 .

It is a cyclic number.

It is not a de Polignac number, because 685681225673 - 2¹⁶ = 685681160137 is a prime.

It is not a weakly prime, because it can be changed into another prime (685681225613) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342840612836 + 342840612837.

It is an arithmetic number, because the mean of its divisors is an integer number (342840612837).

Almost surely, 2^685681225673 is an apocalyptic number.

It is an amenable number.

685681225673 is a deficient number, since it is larger than the sum of its proper divisors (1).

685681225673 is an equidigital number, since it uses as much as digits as its factorization.

685681225673 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 29030400, while the sum is 59.

The spelling of 685681225673 in words is "six hundred eighty-five billion, six hundred eighty-one million, two hundred twenty-five thousand, six hundred seventy-three".