208490209 has 2 divisors, whose sum is σ = 208490210. Its totient is φ = 208490208.

The previous prime is 208490179. The next prime is 208490213. The reversal of 208490209 is 902094802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 166926400 + 41563809 = 12920^2 + 6447^2 .

It is a cyclic number.

It is not a de Polignac number, because 208490209 - 2⁷ = 208490081 is a prime.

It is not a weakly prime, because it can be changed into another prime (208490279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104245104 + 104245105.

It is an arithmetic number, because the mean of its divisors is an integer number (104245105).

Almost surely, 2^208490209 is an apocalyptic number.

It is an amenable number.

208490209 is a deficient number, since it is larger than the sum of its proper divisors (1).

208490209 is an equidigital number, since it uses as much as digits as its factorization.

208490209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10368, while the sum is 34.

The square root of 208490209 is about 14439.1900396109. The cubic root of 208490209 is about 592.9643107512.

The spelling of 208490209 in words is "two hundred eight million, four hundred ninety thousand, two hundred nine".