Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 171: | \[{21^{171}-1\over20}\] | 463 × 28387 × 304609 × 85775383 × 3263277133 × 12061389013<11> × 54921106624003<14> × 1769098309517989<16> × 201773586986282524421768503820293<33> × 1244541772187848099210936765314595053007129<43> × 1906545596109201001931181173321063934469362055720076288290431439788614388343220743<82> |