Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 122: | \[{21^{122}-1\over20}\] | 2 × 11 × 367 × 15373 × 75641 × 12519763 × 15569711981<11> × 1128331159687<13> × 132538677158969693<18> × 1814065850324073713<19> × 37376752870606823789<20> × 9600772802405878717656259<25> × 57398774322642953389748085156004642469<38> |