Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 495: | \[{21^{495}-1\over20}\] | 5 × 67 × 211 × 331 × 463 × 881 × 991 × 3301 × 9391 × 18181 × 40841 × 372901 × 41489011 × 57815101 × 85775383 × 5664205361<10> × 182894303461<12> × 17513875027111<14> × 782006960636353<15> × 22554946693833031<17> × 28503846834226831<17> × 146354764854514987<18> × 270573999780463721<18> × 54598616218616435702441<23> × 3955202198062795629622003<25> × 237967900696723393143507690151891<33> × 12445053671159143233988565211478891<35> × 188145268678304791443009491673532813732054627291<48> × [217072085729371107410299697441596484814058786151116531006156524764526233505418424445871916303359527462523554797363582027913114298266787622758972580355936246441996501561724188445401348582775728078659826435565208561258870694392311509772148809985397026632765213322372773306206222111580257369854881764867138460590288511<315>] |