209

209 = 11 x 19.

209 is the smallest number with six representations as a sum of three squares: 209 = 1² + 8² + 12² = 2² + 3² + 14² = 2² + 6² + 13² = 3² + 10² + 10² = 4² + 7² + 12² = 8² + 8² + 9².

209 is the smallest composite number that is 1 less than a primorial.

209 is the number of consecutive composite numbers that follow the prime 20831323, the first prime gap exceeding 200.

The chemical element bismuth has one stable isotope, which contains 209 neutrons.

Source: Prime Curios!