Base 23 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
53: | \[{23^{53}-1\over22}\] | 107 × 134515657106693<15> × 61190665486751483<17> × 76614476156594621168268977128460059157<38> |