Positive Integers » 20001-30000 » 21901-22000 » 21991
Divisors of the Positive Integer 21991
1, 21991Sum of all the Divisors of 21991, including itself
21992Sum of the Proper Divisors of 21991
1Properties of the number 21991
The integer 21991 is an odd number.The integer 21991 is a Prime number.
1 is less than 21991, so 21991 is a deficient number.
The number 21991 as a Roman Numeral
_X_XMCMXCI (Roman Numerals with underscores in front have their values increased by 1,000. The underscore represents a line over the numeral, because the Romans used overlines to multiply by 1,000.)The number 21991 in various Numeral Systems
| Base | Representation |
|---|---|
| 2: | 101010111100111 |
| 3: | 1010011111 |
| 4: | 11113213 |
| 5: | 1200431 |
| 6: | 245451 |
| 7: | 121054 |
| 8: | 52747 |
| 9: | 33144 |
| 10: | 21991 |
| 11: | 15582 |
| 12: | 10887 |
| 13: | A018 |
| 14: | 802B |
| 15: | 67B1 |
| 16: | 55E7 |
| 17: | 481A |
| 18: | 3DFD |
| 19: | 33H8 |
| 20: | 2EJB |
| 21: | 27I4 |
| 22: | 219D |
| 23: | 1ID3 |
| 24: | 1E47 |
| 25: | 1A4G |
| 26: | 16DL |
| 27: | 134D |
| 28: | 101B |
| 29: | Q49 |
| 30: | OD1 |
| 31: | MRC |
| 32: | LF7 |
| 33: | K6D |
| 34: | J0R |
| 35: | HXB |
| 36: | GYV |