Base 26 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
53: | \[{26^{53}-1\over25}\] | 4241 × 150097 × 358043142577<12> × 1971203353831<13> × 87728430468489003278234446945154202781697<41> |