$17$ was the highest number whose square root was proved irrational by Theodorus of Cyrene.
Plutarch reports that the Pythagoreans had a horror of the number $17$.
That was because it lay half way between $16$ and $18$, which are the areas of rectangles whose areas equal their perimeters.
$17$ seems to be a popular age to write a pop song about:
to name but three.