Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 147: | \[{21^{147}-1\over20}\] | 43 × 463 × 631 × 3319 × 4789 × 6427 × 7057 × 17053 × 1287133 × 1519099 × 227633407 × 1606344741163<13> × 1767442850839<13> × 266450990381897623<18> × 1703751007820049542146461103<28> × 7511823115405357369289846817961357<34> × 17460141974669146302241107654783887359178281<44> |