Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 144: | \[{21^{144}-1\over20}\] | 24 × 11 × 13 × 17 × 19 × 37 × 61 × 73 × 193 × 199 × 421 × 433 × 463 × 613 × 673 × 1693 × 3181 × 62897 × 97241 × 300673 × 816769 × 1001713 × 25392481 × 85775383 × 518118697 × 808208209 × 4344847859197<13> × 4116371120264449<16> × 81967288802253121<17> × 711232550734200751494958531511588181663062004769<48> |