685204140197 has 2 divisors, whose sum is σ = 685204140198. Its totient is φ = 685204140196.

The previous prime is 685204140041. The next prime is 685204140199. The reversal of 685204140197 is 791041402586.

It is a happy number.

685204140197 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 550721315236 + 134482824961 = 742106^2 + 366719^2 .

It is a cyclic number.

It is not a de Polignac number, because 685204140197 - 2⁸ = 685204139941 is a prime.

It is a super-2 number, since 2×685204140197² (a number of 24 digits) contains 22 as substring.

Together with 685204140199, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685204140199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342602070098 + 342602070099.

It is an arithmetic number, because the mean of its divisors is an integer number (342602070099).

Almost surely, 2^685204140197 is an apocalyptic number.

It is an amenable number.

685204140197 is a deficient number, since it is larger than the sum of its proper divisors (1).

685204140197 is an equidigital number, since it uses as much as digits as its factorization.

685204140197 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 483840, while the sum is 47.

The spelling of 685204140197 in words is "six hundred eighty-five billion, two hundred four million, one hundred forty thousand, one hundred ninety-seven".