Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 209: | \[{21^{209}-1\over20}\] | 419 × 12061389013<11> × 17513875027111<14> × 54921106624003<14> × 698778642379357<15> × [32488533444474748429097762128834648665461793264269052039618788251577267327920042082097438138462106295033577482853888654925901341523332661531021123172375196712064529620089795372849082842819274218191297678350283693407940847<221>] |