The number 489
489 is a composite number with 4 divisors. Its prime factorisation is 3 × 163. Divisors (4): 1, 3, 163, 489.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 489: a semiprime: 3 × 163, the product of two primes.
- 2
489 is composite. Its prime factorisation is
- 3
The divisors add up to 656; without 489 itself that is 167, so 489 is deficient (167 is less than 489). Euler's totient φ(489) = 324 numbers up to 489 share no factor with it.
- 4
The digits of 489 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 48 steps to reach 1.
LaTeX source of the formulas on this page
\[ 489 = 3 \times 163 \]
489 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 656 |
| Euler totient φ(n) | 324 |
| Square | 239121 |
| Cube | 116930169 |
| Square root | 22.113344 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 48 |
| Scientific notation | 4.89 × |
489 in other forms
| Form | Value |
|---|---|
| In words | four hundred and eighty-nine |
| Roman numerals | CDLXXXIX |
| Binary (base 2) | 111101001 |
| Octal (base 8) | 751 |
| Hexadecimal (base 16) | 1E9 |
| Base 3 | 200010 |
| As time | 489 seconds = 8 min 9 s |
Is 489 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 (489 ÷ 3 = 163) | 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 6) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | 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 5) | 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 489 a prime number?
No. 489 = 3 × 163, so it is divisible by 3.
What are the factors of 489?
1, 3, 163, 489.
What is 489 in binary?
111101001 (hexadecimal 1E9, octal 751).
What is the square root of 489?
About 22.1133.
What is 489 in Roman numerals?
CDLXXXIX.
Is 489 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 489?
489 is a semiprime: 3 × 163, the product of two primes.