1001 in Binary = 9 in Decimal
1001 in binary is
9 in decimal, IX in Roman numerals, 9 in hexadecimal and 11 in octal.
1001 binary = 9 decimal
1001 in every number system
| System | Written as |
|---|---|
| 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 |
| Quaternary (base 4) | 21 |
| Quinary (base 5) | 14 |
| Senary (base 6) | 13 |
How to read 1001 in binary
Binary to decimal
Multiply each digit by 2 to the power of its position (0 on the right), then add:
| Digit | Place value | Digit × place |
|---|---|---|
1 | 23 = 8 | 8 |
0 | 22 = 4 | 0 |
0 | 21 = 2 | 0 |
1 | 20 = 1 | 1 |
8 + 0 + 0 + 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.