odd, composite · 129th positive integer
The number 129
129 is an odd composite number. It is the 129th positive integer.
Quick reference
| Prime factorization | 3 × 43 |
| Divisors | 1, 3, 43, 129 |
| Binary | 10000001 |
| Hexadecimal | 0x81 |
| Roman numeral | CXXIX |
| Digit sum | 12 |
| Properties | odd, composite |
Frequently asked
Is 129 a prime number?
No. 129 is composite. Its prime factorization is 3 × 43.
What are the factors of 129?
The factors (divisors) of 129 are 1, 3, 43, 129.
What is 129 in binary?
129 in binary is 10000001. In hexadecimal it's 81.
What is 129 as a Roman numeral?
129 in Roman numerals is CXXIX.
What's the digit sum of 129?
Adding the digits of 129: 1 + 2 + 9 = 12.