685697 has 2 divisors, whose sum is σ = 685698. Its totient is φ = 685696.

The previous prime is 685679. The next prime is 685717. The reversal of 685697 is 796586.

It is a happy number.

Together with previous prime (685679) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 602176 + 83521 = 776^2 + 289^2 .

It is a cyclic number.

It is not a de Polignac number, because 685697 - 2¹⁶ = 620161 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (685637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342848 + 342849.

It is an arithmetic number, because the mean of its divisors is an integer number (342849).

2⁶⁸⁵⁶⁹⁷ is an apocalyptic number.

It is an amenable number.

685697 is a deficient number, since it is larger than the sum of its proper divisors (1).

685697 is an equidigital number, since it uses as much as digits as its factorization.

685697 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 41.

The square root of 685697 is about 828.0682339035. The cubic root of 685697 is about 88.1814866798.

Subtracting 685697 from its reverse (796586), we obtain a square (110889 = 333²).

The spelling of 685697 in words is "six hundred eighty-five thousand, six hundred ninety-seven".