Base 9 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 81: | \[{9^{81}-1\over8}\] | 7 × 13 × 19 × 37 × 109 × 163 × 433 × 757 × 1297 × 3889 × 8209 × 19441 × 19927 × 208657 × 224209 × 1190701 × 5879415781<10> × 12557612956332313<17> |