685849 has 2 divisors, whose sum is σ = 685850. Its totient is φ = 685848.

The previous prime is 685819. The next prime is 685859. The reversal of 685849 is 948586.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 632025 + 53824 = 795^2 + 232^2 .

It is a cyclic number.

It is not a de Polignac number, because 685849 - 2⁹ = 685337 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (685819) 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, 342924 + 342925.

It is an arithmetic number, because the mean of its divisors is an integer number (342925).

2⁶⁸⁵⁸⁴⁹ is an apocalyptic number.

It is an amenable number.

685849 is a deficient number, since it is larger than the sum of its proper divisors (1).

685849 is an equidigital number, since it uses as much as digits as its factorization.

685849 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 69120, while the sum is 40.

The square root of 685849 is about 828.1600086940. The cubic root of 685849 is about 88.1880019947.

The spelling of 685849 in words is "six hundred eighty-five thousand, eight hundred forty-nine".