Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 646: | \[{21^{646}-1\over20}\] | 2 × 11 × 647 × 11969 × 35531 × 505819 × 609673 × 4184143 × 95898701 × 187287029 × 12061389013<11> × 54921106624003<14> × 114089969144083169<18> × 987749814642143197<18> × 1502097124754084594737<22> × [1664373956982708898952239366090666917081455254998879872755676469621790034864373741993457723146626906186821211446084862137000176129454505635598985283044802091695872038411353182247512452532224498777188297102357651259643384383169871220067118364693001577732106780785155345771891500245273751064064433294885945145531412513752233115121042259084659454805102029525818217<361>] × 272046503541850654234010302146342345570640171090338173567746947293309147746183077692257432088823368287678545480437736812954227805580683431052236592792803195729909281010447401138255409097659927294935493904570578876591559013240332128411729634496024248849424479180897548475709226328865354262488980951701630329509387504198734899729023181736374880518416915629785505220633<366> |