Base 20 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 646: | \[{20^{646}-1\over19}\] | 3 × 7 × 19 × 647 × 134369 × 2567783 × 2640509 × 38136611 × 92054423 × 75368484119<11> × 109850818001<12> × 192696104561<12> × 2272727294381<13> × 13222527711806339<17> × 124088638104045007<18> × 689852631578947368421<21> × [6972791651644890346265458984337553514290090047011260649127962845814162682316067874628183788723291922206213469615084978127983825397083172758555529002034169127879611314764652440861823064618964844211585479670654108563665047149965302604311387857298425991862234046353895471079406954453277592110684654484218460507086815282324485635068632551433610245381<346>] × [6504168016811212641503640266062612428008040506838592715217440045040894895021687211466443531520730967607567045164259317736016544052744237650703236357750644221685628627352175707597463779645105743611522466644685212451931663221691693494814493827212773853271429606192796702126209047403526272324410883527147553379193933243182917979429144101148350504182003623949<355>] |