odd, prime, Fibonacci, triangular, palindrome · 3rd positive integer
The number 3
3 is an odd prime number. It's known as the smallest odd prime and the second prime. It is the 3rd positive integer.
Quick reference
| Prime factorization | 3 (prime) |
| Divisors | 1, 3 |
| Binary | 11 |
| Hexadecimal | 0x3 |
| Roman numeral | III |
| Digit sum | 3 |
| Properties | odd, prime, Fibonacci, triangular, palindrome |
Why 3 is notable
The smallest odd prime and the second prime.
Frequently asked
Is 3 a prime number?
Yes. 3 is prime — its only divisors are 1 and itself.
What are the factors of 3?
The factors (divisors) of 3 are 1, 3.
What is 3 in binary?
3 in binary is 11. In hexadecimal it's 3.
What is 3 as a Roman numeral?
3 in Roman numerals is III.
What's the digit sum of 3?
Adding the digits of 3: 3 = 3.