Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 238: | \[{21^{238}-1\over20}\] | 2 × 11 × 43 × 239 × 631 × 3319 × 11969 × 14281 × 44983 × 78541 × 81867661 × 114089969144083169<18> × 1502097124754084594737<22> × 2799538602198455356994757392557147<34> × 228981930777446745490310485965805923037<39> × 19822950076647947256661837016844167085154211713<47> × 456547149396215146316989552005017911648766803061935886988961<60> × 1047793542046228932239094186657681797677507847051755213152299<61> |