206209 has 2 divisors, whose sum is σ = 206210. Its totient is φ = 206208.

The previous prime is 206203. The next prime is 206221. The reversal of 206209 is 902602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 199809 + 6400 = 447^2 + 80^2 .

It is a cyclic number.

It is not a de Polignac number, because 206209 - 2⁵ = 206177 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (206203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103104 + 103105.

It is an arithmetic number, because the mean of its divisors is an integer number (103105).

2²⁰⁶²⁰⁹ is an apocalyptic number.

It is an amenable number.

206209 is a deficient number, since it is larger than the sum of its proper divisors (1).

206209 is an equidigital number, since it uses as much as digits as its factorization.

206209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 206209 is about 454.1024113567. The cubic root of 206209 is about 59.0793722501.

The spelling of 206209 in words is "two hundred six thousand, two hundred nine".