The folowing table expresses '780' 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 | 1100001100 | 100 | 1 | |||||||
| 3 | 1001220 | 20 | 2 | |||||||
| 4 | 30030 | 12 | 3 | |||||||
| 5 | 11110 | 4 | ||||||||
| 6 | 3340 | 14 | 5 | |||||||
| 7 | 2163 | 15 | 6 | |||||||
| 8 | 1414 | 12 | 3 | |||||||
| 9 | 1056 | 13 | 4 | |||||||
| 10 | 780 | 15 | 6 | |||||||
| 11 | 64A | 19 | A | |||||||
| 12 | 550 | A | ||||||||
| 13 | 480 | C | ||||||||
| 14 | 3DA | 1C | D | |||||||
| 15 | 370 | A | ||||||||
| 16 | 30C | F |
Factors: 22 * 3 * 5 * 13
780 is in the Pythagorean Triples: (780, 1421, 1621), (451, 780, 901), (731, 780, 1069).
780 is the sum of the counting numbers from 1 to 39 (See 'The Sum/Product of the First N Counting Numbers').