odd, composite, triangular · 15th positive integer
The number 15
15 is an odd composite number. It is the 15th positive integer.
Quick reference
| Prime factorization | 3 × 5 |
| Divisors | 1, 3, 5, 15 |
| Binary | 1111 |
| Hexadecimal | 0xF |
| Roman numeral | XV |
| Digit sum | 6 |
| Properties | odd, composite, triangular |
Frequently asked
Is 15 a prime number?
No. 15 is composite. Its prime factorization is 3 × 5.
What are the factors of 15?
The factors (divisors) of 15 are 1, 3, 5, 15.
What is 15 in binary?
15 in binary is 1111. In hexadecimal it's F.
What is 15 as a Roman numeral?
15 in Roman numerals is XV.
What's the digit sum of 15?
Adding the digits of 15: 1 + 5 = 6.