685369 has 2 divisors, whose sum is σ = 685370. Its totient is φ = 685368.

The previous prime is 685367. The next prime is 685381. The reversal of 685369 is 963586.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 640000 + 45369 = 800^2 + 213^2 .

It is a cyclic number.

It is not a de Polignac number, because 685369 - 2¹ = 685367 is a prime.

It is a super-2 number, since 2×685369² = 939461332322, which contains 22 as substring.

Together with 685367, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (685361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342684 + 342685.

It is an arithmetic number, because the mean of its divisors is an integer number (342685).

2⁶⁸⁵³⁶⁹ is an apocalyptic number.

It is an amenable number.

685369 is a deficient number, since it is larger than the sum of its proper divisors (1).

685369 is an equidigital number, since it uses as much as digits as its factorization.

685369 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 38880, while the sum is 37.

The square root of 685369 is about 827.8701589017. The cubic root of 685369 is about 88.1674240347.

The spelling of 685369 in words is "six hundred eighty-five thousand, three hundred sixty-nine".