The folowing table expresses '91' in various number bases. 'DRx' shows the result of 'digit reducing' resulting in an X-digit long number.
Base | DR7 | DR6 | DR5 | DR4 | DR3 | DR2 | DR1 |
---|---|---|---|---|---|---|---|
2 | 1011011 | 101 | 10 | 1 | |||
3 | 10101 | 10 | 1 | ||||
4 | 1123 | 13,10 | 1 | ||||
5 | 331 | 12 | 3 | ||||
6 | 231 | 10 | 1 | ||||
7 | 160 | 10 | 1 | ||||
8 | 133 | 7 | |||||
9 | 111 | 3 | |||||
10 | 91,10 | 1 | |||||
11 | 83,10 | 1 | |||||
12 | 77,12 | 3 | |||||
13 | 70 | 7 | |||||
14 | 67 | D | |||||
15 | 61 | 7 | |||||
16 | 5B,10 | 1 |
Factors: 7 * 13
91 is in the Pythagorean Triples: (60, 91, 109), (91, 4140, 4141).
91 is the sum of the counting numbers from 1 to 13 (See 'The Sum/Product of the First N Counting Numbers').
91 is the atomic weight of Protactinium (Pa).