Base 28 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 139: | \[{28^{139}-1\over27}\] | 557 × 1849232948929997<16> × 8643084822957942510456233827072399990947602214550459523018202141644918926379<76> × 5944112208740897667284826518545495081578428861831055621283133129397782126168538429755918021189417535597263<106> |