The number 549
549 is a composite number with 6 divisors. Its prime factorisation is × 61. Divisors (6): 1, 3, 9, 61, 183, 549.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
549 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
549 is composite. Its prime factorisation is
- 3
The divisors add up to 806; without 549 itself that is 257, so 549 is deficient (257 is less than 549). Euler's totient φ(549) = 360 numbers up to 549 share no factor with it.
- 4
The digits of 549 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 92 steps to reach 1.
LaTeX source of the formulas on this page
\[ 549 = 3^{2} \times 61 \]549 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 806 |
| Euler totient φ(n) | 360 |
| Square | 301401 |
| Cube | 165469149 |
| Square root | 23.430749 (= 3√61) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 92 |
| Scientific notation | 5.49 × |
549 in other forms
| Form | Value |
|---|---|
| In words | five hundred and forty-nine |
| Roman numerals | DXLIX |
| Binary (base 2) | 1000100101 |
| Octal (base 8) | 1045 |
| Hexadecimal (base 16) | 225 |
| Base 3 | 202100 |
| As time | 549 seconds = 9 min 9 s |
Is 549 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (549 ÷ 3 = 183) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | A number is divisible by 7 if double the last digit and subtract it from the rest: the result is a multiple of 7. |
| 8 | No (remainder 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (549 ÷ 9 = 61) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 9) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 549 a prime number?
No. 549 = × 61, so it is divisible by 3.
What are the factors of 549?
1, 3, 9, 61, 183, 549.
What is 549 in binary?
1000100101 (hexadecimal 225, octal 1045).
What is the square root of 549?
About 23.4307, exactly 3√61.
What is 549 in Roman numerals?
DXLIX.
Is 549 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 549?
It is a composite number with 6 divisors.