Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 167: | \[{21^{167}-1\over20}\] | 1102201 × 19470197 × 20231878724432159106473151940489466149676377569946589675188861313754293570228700650486980343491462439<101> × 7446031435458004141923577009324871384387277476816498485650562324308647434520507573854037042870112336785089<106> |