Hello Math-Fun, according to this page, http://www.primepuzzles.net/puzzles/puzz_457.htm "the smallest prime number whose name written in English contains the letters "PRIME" in order embedded in it" is ("For American and Modern British English"): 1000000000000000035000061 one sePtillion thiRty-fIve Million sixty-onE - - - - - Similarily, what would be the smallest PENTAGONAL? Best, É.