Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 120: | \[{21^{120}-1\over20}\] | 23 × 5 × 11 × 13 × 17 × 31 × 41 × 61 × 73 × 211 × 421 × 463 × 601 × 2551 × 3181 × 9391 × 18181 × 40841 × 97241 × 185641 × 501001 × 1360861 × 3441241 × 40086001 × 518118697 × 920421641 × 415710882920521<15> × 1053606939618901<16> × 84947863319467630678021906123321<32> |