Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 414: | \[{21^{414}-1\over20}\] | 2 × 11 × 19 × 37 × 47 × 139 × 199 × 277 × 421 × 461 × 463 × 599 × 613 × 691 × 3313 × 19597 × 85775383 × 119807047 × 459878292118921111<18> × 2215825387044753577<19> × 110173915920133084951<21> × 139870566115103282847737<24> × 3384589507843147005879370009<28> × 56359728231197572655147103751<29> × 35578422243168543619641172951507<32> × 31179105887601949149105715319437017328831<41> × 113446385036884293778618204054931232136334832994350798619<57> × 4286811848148134933547151603444347205061882372362049653691118717490623731439267847880249445635287570723<103> × 9147769599005285165059853711940714465612730316340092611818747685472062074458750462990178604106947837354893313548037617430835719<127> |