685906853 has 2 divisors, whose sum is σ = 685906854. Its totient is φ = 685906852.

The previous prime is 685906813. The next prime is 685906901. The reversal of 685906853 is 358609586.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 681314404 + 4592449 = 26102^2 + 2143^2 .

It is a cyclic number.

It is not a de Polignac number, because 685906853 - 2⁸ = 685906597 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685906813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342953426 + 342953427.

It is an arithmetic number, because the mean of its divisors is an integer number (342953427).

Almost surely, 2^685906853 is an apocalyptic number.

It is an amenable number.

685906853 is a deficient number, since it is larger than the sum of its proper divisors (1).

685906853 is an equidigital number, since it uses as much as digits as its factorization.

685906853 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1555200, while the sum is 50.

The square root of 685906853 is about 26189.8234625589. The cubic root of 685906853 is about 881.9048154781.

The spelling of 685906853 in words is "six hundred eighty-five million, nine hundred six thousand, eight hundred fifty-three".