Base 19 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 87: | \[{19^{87}-1\over18}\] | 3 × 59 × 127 × 233 × 349 × 1230181 × 1243579 × 2997499 × 20736451 × 297003021451861<15> × 165049085515149863<18> × 1340588661158222617<19> × 8680146187079648246848027<25> |