english: I won't go into great detail as to why, because most of your eyes will bleed out of your head if I do, but suffice to say, a number of that form is fairly easy to test for primacy.
non_english: Nepôjdem do detailov, prečo to tak je, pretože väčšine z vás by z toho explodovala hlava, ale postačí povedať, že pri čísle v takom tvare sa dá pomerne ľahko skontrolovať, či ide o prvočíslo.