Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 236: | \[{21^{236}-1\over20}\] | 22 × 11 × 13 × 17 × 3541 × 896447 × 334217419 × 3085597813 × 47540111129611360301<20> × 426127435115926103911806312233<30> × 3599933694931243085497791696053868938364103<43> × 15106936038203961355993446093478189757934421447231148098564025562337<68> × 1576845294536005169027446701118790911711585363508624503093306173867398306499565974926862493117514192335208002524984641837<121> |