yes, indeed.
I was speaking just about the possible values of n which are prime numbers.
The real statement is that the "constructible" polygons have n = 2 times 2...times 2 (any number of times) times again p1 times p2...times pw, where p1,p2,...,pw are distinct primes of the kind I was saying before. I could write the rule, if I had a mathematical editor.

So, 6 = 2 times 3 is ok.