Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 254: | \[{21^{254}-1\over20}\] | 2 × 11 × 509 × 3049 × 85853 × 123564234215209<15> × 526073566316093<15> × 21045416332383383<17> × 3023767784043644159<19> × 525212323217088996809<21> × 14948184961120158829387<23> × 6619201108364006378440292620708869500505245589624095987<55> × 105546738449008968050440888723415799976700232611051102641043<60> × 524564045386279138033219804241183578649565761983063373697101770052236095818825177938399303025183058937<102> |