21 in Quaternary = 9 in Decimal
21 in quaternary is
1001 in binary, 9 in decimal, IX in Roman numerals and 9 in hexadecimal.
21 quaternary = 9 decimal
21 in every number system
| System | Written as |
|---|---|
| Binary (base 2) | 1001 |
| Decimal (base 10) | 9 |
| Roman numerals | IX |
| Hexadecimal (base 16) | 9 |
| Octal (base 8) | 11 |
| Duodecimal (base 12) | 9 |
| Ternary (base 3) | 100 |
| Base 36 | 9 |
| Vigesimal (base 20) | 9 |
| Quinary (base 5) | 14 |
| Senary (base 6) | 13 |
How to read 21 in quaternary
Quaternary to decimal
Multiply each digit by 4 to the power of its position (0 on the right), then add:
| Digit | Place value | Digit × place |
|---|---|---|
2 | 41 = 4 | 8 |
1 | 40 = 1 | 1 |
8 + 1 = 9
About the number 9
- 9 is an odd number.
- 9 is not a prime number.
- 9 is a perfect square: 3 × 3.
- Written in binary it needs 4 bits, so it fits in one byte.