Base 20 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 115: | \[{20^{115}-1\over19}\] | 11 × 61 × 251 × 691 × 1381 × 3221 × 15899671 × 393682721 × 1187631911 × 2171940587581<13> × 46266279097921483078651<23> × 7938685883284687902899551<25> × 7121307273752901983750606756745314224670092894931<49> |