Base 20 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 153: | \[{20^{153}-1\over19}\] | 421 × 3061 × 60589 × 202879 × 983179 × 15757471 × 64008001 × 418593619 × 689852631578947368421<21> × 2200293635138152581356053802893789<34> × 93432652605894895875162038827552650472442321569<47> × 644433049745505939538877970119459740656371232594481<51> |