Base 20 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 447: | \[{20^{447}-1\over19}\] | 421 × 1789 × 17881 × 120691 × 144829 × 163901 × 19276573847161<14> × 1349365558297441<16> × 2875786039296613518480371<25> × 136828116178036462392891451<27> × 359650956894840270671011124036564286254529303363586299985258919<63> × 1239094859540391646850133267166414951756710984463954794178330003735400871255583432321065920794109<97> × 108687860228493443326930229119273471386986162937153645183022263349400260163402249110988234903550141763231494253312649527374340919316156810421641313020280673993475863103811025381907898485427344527983772626008040318151938470205168171943722029494362194864439673507441344185775713081949677457854415474437388661399875078861<318> |