The folowing table expresses '666' in various number bases. 'DRx' shows the result of 'digit reducing' resulting in an X-digit long number.
| Base | DR10 | DR9 | DR8 | DR7 | DR6 | DR5 | DR4 | DR3 | DR2 | DR1 |
|---|---|---|---|---|---|---|---|---|---|---|
| 2 | 1010011010 | 101 | 10 | 1 | ||||||
| 3 | 220200 | 20 | 2 | |||||||
| 4 | 22122 | 21 | 3 | |||||||
| 5 | 10131 | 11 | 2 | |||||||
| 6 | 3030 | 10 | 1 | |||||||
| 7 | 1641 | 15 | 6 | |||||||
| 8 | 1232 | 10 | 1 | |||||||
| 9 | 820 | 11 | 2 | |||||||
| 10 | 666 | 18 | 9 | |||||||
| 11 | 556 | 15 | 6 | |||||||
| 12 | 476 | 15 | 6 | |||||||
| 13 | 3C3 | 15 | 6 | |||||||
| 14 | 358 | 12 | 3 | |||||||
| 15 | 2E6 | 17 | 8 | |||||||
| 16 | 29A | 15 | 6 |
Factors: 2 * 32 * 37
666 is the sum of the counting numbers from 1 to 36 (See 'The Sum/Product of the First N Counting Numbers').