Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 405: | \[{21^{405}-1\over20}\] | 5 × 109 × 163 × 211 × 463 × 1621 × 9391 × 18181 × 40841 × 4779433 × 41489011 × 57815101 × 85775383 × 2366716321 × 7429452749713<13> × 192787782171121<15> × 22554946693833031<17> × 2447244788249267691839821<25> × 335762586163588511737475534667790066590701118595773133381<57> × 251097226443098886970664441840231990201201851332912023687544574398706423<72> × [1036187722077767829493517677047433165660831633634295241983208389470357200800251836976378548099046964201270276943988760573334824403864207626540939722751857773839425702556321352079382754551040972892548114367914013520646159350041812500461903141653112315691014242917495577423021<274>] |