Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
121: | \[{21^{121}-1\over20}\] | 17513875027111<14> × 25400947557093092161<20> × 1094642996710826219735129227785915893367653427444929746456584017045151470091370769903278728324073277790247936858477306484443951<127> |