Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 374: | \[{21^{374}-1\over20}\] | 2 × 112 × 23 × 1871 × 6073 × 11969 × 51239 × 1172491 × 10362529 × 17513875027111<14> × 114089969144083169<18> × 765464515091513689<18> × 21871159470059504243<20> × 1502097124754084594737<22> × 975445747250107665555691903049<30> × 893653232599703974920871369442322429783560168273312923073800591562358852946149890611480777927863456119289243404490761977035905704889551283604368072835558008119<159> × 783854455148757362969145723656842904021421889418188258772468900355180745296703650579611401310359649092364790062438722545359440916748348039026145534145999441204331888777994218294321887<183> |