Base 5 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 391: | \[{5^{391}-1\over4}\] | 409 × 8971 × 2568871 × 74708371 × 466344409 × 311250747739<12> × 332207361361<12> × 416079604348810289<18> × 787775103387484980951811308682438561347569<42> × 553265630385022055666695438035664111456941805599247964204695144048160899<72> × 80500240108620821600554970587125841775999919410290262911667706097023511257891861551435581<89> |