Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 124: | \[{21^{124}-1\over20}\] | 22 × 11 × 13 × 17 × 66713 × 78059 × 92753 × 4540713283<10> × 3936833990413<13> × 272581865551637989<18> × 13163658325422541897<20> × 56748249908554278937564172324714039<35> × 263790388079541107039607586199349904436518481062297<51> |