Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 205: | \[{21^{205}-1\over20}\] | 5 × 83 × 36901 × 40841 × 5271781 × 14122861 × 83218931 × 15302729711<11> × 17222085343<11> × 914531249431<12> × 52899783148909<14> × 11485067744219942708886592974523772674194839220685020253423476954547777123419460060388102679004871367799202337124266639742374928164453078749557472220999623096360348281702421577544673717017511<191> |