Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 224: | \[{21^{224}-1\over20}\] | 25 × 11 × 13 × 17 × 29 × 43 × 113 × 617 × 631 × 1217 × 2689 × 3319 × 3697 × 12097 × 31873 × 62897 × 97241 × 300673 × 912521 × 81867661 × 290685697 × 6857635489<10> × 68454248717<11> × 115593326297<12> × 360058801537<12> × 831380909129<12> × 31548272195219921<17> × 936467984954383841<18> × 67888223448153422105362819002556545290401<41> × 87450493576622721619527753467135154239906988598728664231668992479969380242355342027217889<89> |