Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
60: | \[{21^{60}-1\over20}\] | 22 × 5 × 11 × 13 × 17 × 31 × 41 × 61 × 211 × 421 × 463 × 2551 × 3181 × 9391 × 18181 × 40841 × 185641 × 501001 × 1360861 × 920421641 × 1053606939618901<16> |