Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 252: | \[{21^{252}-1\over20}\] | 22 × 11 × 13 × 17 × 19 × 29 × 37 × 43 × 61 × 127 × 199 × 337 × 421 × 463 × 613 × 631 × 1693 × 3181 × 3319 × 3697 × 4789 × 6427 × 18481 × 51787 × 516349 × 734329 × 81867661 × 85775383 × 227633407 × 3462803569 × 22125429901<11> × 68454248717<11> × 272314707337<12> × 4344847859197<13> × 22864311556633<14> × 27186384126763<14> × 4527391635851869<16> × 100595851688887003<18> × 231877932177836345689<21> × 2934413293238858072198024161<28> × 38879383462474983799014142129<29> × 4320867038579967046737930247423422292651004233<46> |