cool

Yes. bitwise-or of the modulo(remainder). It is only zero if both modulos are zero.
When using it on bools you have to be a bit careful, as (1 | 2) is 0011, and that is stored in boolean. true is 0001, so while (1 | 2) evalutes to true, it's not equal to true in some way. Here it's fine, but be aware. Negating with ! (boolean not) "normalizes" it to 0000 or 0001 though. ~ would be the bitwise not.

bitwise-or may be faster as it does not branch (both sides are always evaluated), as opposed to boolean or. But don't rely on that.

is this the bitwise OR operator?

nice man good job ?? !!

it's really clever but indentation is not very good.

nice coding

The easiest to undestand of them all.

Incredible!

This is the most brilliant thing I have ever seen!

Really clever! Avoided so many unnecessary steps.

You would'n come into a situation to divide by ex. 9 or 14, cause you would've already divided the number by their prime decomposers 2, 3 and 7. Thus no need to check for primality.

Very intelligent!

Very elegant!

Beautiful!

Very nice!