Base 20 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 157: | \[{20^{157}-1\over19}\] | 60289 × 33199849 × 63308681 × 4913435742983744898735077696629<31> × 495845966219627019845467844310809<33> × 491555142694969830320939587474332477478073309<45> × 633598229051514050706041708321772637750765843640528540048669316801619307069<75> |