Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 189: | \[{21^{189}-1\over20}\] | 43 × 109 × 127 × 163 × 379 × 463 × 631 × 757 × 3319 × 4789 × 6427 × 51787 × 4779433 × 85775383 × 227633407 × 4167831781 × 22125429901<11> × 7429452749713<13> × 27186384126763<14> × 100595851688887003<18> × 559529226207687925351<21> × 592823611828574163154462624637481670158792334981<48> × 158960891807692552808356500085059265746129175440701992893457<60> |