Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 226: | \[{21^{226}-1\over20}\] | 2 × 11 × 227 × 1583 × 91079 × 332447 × 768053632358191<15> × 97402954580003507<17> × 1910857511744965027<19> × 2848908845742998189988598903<28> × 13882020027413204621222579528393197501<38> × 5616674628667674074541197792169903784792943111117930947154929<61> × 436172239267866932302894149650912586526420521525252665777376116689125207469892569181075019466356249100577<105> |