Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 210: | \[{21^{210}-1\over20}\] | 2 × 5 × 11 × 31 × 43 × 71 × 211 × 337 × 421 × 463 × 631 × 1471 × 2551 × 3319 × 4789 × 6427 × 9391 × 18181 × 20161 × 40841 × 140351 × 185641 × 501001 × 4149601 × 20028751 × 78555121 × 81090871 × 81867661 × 227633407 × 3987476221 × 16128844201<11> × 22864311556633<14> × 421503321597121<15> × 72413241922093801<17> × 5124240195826801224421<22> × 268004127903031206150241<24> × 1855106691418101398774071<25> × 32071033873519074932758681<26> |