206009 has 2 divisors, whose sum is σ = 206010. Its totient is φ = 206008.

The previous prime is 205993. The next prime is 206021. The reversal of 206009 is 900602.

206009 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., 157609 + 48400 = 397^2 + 220^2 .

It is a cyclic number.

It is not a de Polignac number, because 206009 - 2⁴ = 205993 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (206039) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103004 + 103005.

It is an arithmetic number, because the mean of its divisors is an integer number (103005).

2²⁰⁶⁰⁰⁹ is an apocalyptic number.

It is an amenable number.

206009 is a deficient number, since it is larger than the sum of its proper divisors (1).

206009 is an equidigital number, since it uses as much as digits as its factorization.

206009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 206009 is about 453.8821432927. The cubic root of 206009 is about 59.0602659122.

The spelling of 206009 in words is "two hundred six thousand, nine".