Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 195: | \[{21^{195}-1\over20}\] | 5 × 79 × 131 × 211 × 463 × 547 × 1171 × 9391 × 18181 × 40841 × 189437 × 443431 × 516094151 × 702978785993374112119171<24> × 80459337199345300130638393<26> × 47999819885150422820855221255204479443163906801765079421<56> × 12801249738878817126188071191894856280718343847929106839732904881739093191476709420994139418551374413291<104> |