Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 525: | \[{21^{525}-1\over20}\] | 52 × 43 × 151 × 211 × 463 × 631 × 1051 × 1471 × 1801 × 3319 × 4789 × 6427 × 9391 × 18181 × 40841 × 81901 × 2031851 × 4149601 × 20028751 × 81090871 × 227633407 × 3987476221 × 9728219701<10> × 24602533201<11> × 201307465501<12> × 421503321597121<15> × 11359920545268751<17> × 27385718497004633851<20> × 5124240195826801224421<22> × 138288178346489520230701<24> × 1855106691418101398774071<25> × 37686242599452410706868538086801<32> × 6107498812503060189977652663684219147254525910663051537427182386752756045066004222730822829713729595685422017301<112> × 40733838078918893142174788903639743594735000943325583883467125956243406594284250493077676573268383011682151923174089151110661203229537255897951<143> × [464836493031141830077695066325343109139630173223318077908167403384078615757780526274523912959374519495197567619838649416071769228148987591292956891364286749201<159>] |