Base 20 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 390: | \[{20^{390}-1\over19}\] | 32 × 7 × 11 × 31 × 61 × 79 × 127 × 131 × 251 × 421 × 521 × 1171 × 2081 × 2549 × 3001 × 3121 × 3511 × 4421 × 90481 × 142559 × 152381 × 261451 × 403261 × 1340743 × 9690539 × 571945141 × 735408649 × 4470064171<10> × 12831155611<11> × 26876632021<11> × 144142570154831<15> × 22969682841393367<17> × 27814122544522861<17> × 34458786390125761<17> × 37217519646710509861<20> × 4329520082233745656921<22> × 172311318287603732461390609<27> × 11477196436840183082171551292108543731<38> × 8576872958936563675632381117677636409904152661<46> × 37728220072591903594777394062315785248115734924892661<53> × 2713184579409103809292154246585527965270139017142928097322663516731988290161885305777362819078278612195242321<109> |