Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
166: | \[{21^{166}-1\over20}\] | 2 × 11 × 167 × 756131 × 941221 × 340541835197467124476215159811<30> × 59923443964076110556880753544175063<35> × 123598028795681525040744945941933185295442497<45> × 23343519976297040387448341592997138604460338237413223529466429945751726176986579124533941307079<95> |