Base 31 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 69: | \[{31^{69}-1\over30}\] | 3 × 139 × 331 × 1164859 × 1509997 × 61562537 × 2553526979752336381<19> × 7176374761323733117<19> × 975573640291548852951234645170717556781<39> |