The number 490
490 is a composite number with 12 divisors. Its prime factorisation is 2 × 5 × . Divisors (12): 1, 2, 5, 7, 10, 14, 35, 49, 70, 98, 245, 490.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 490: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
490 is composite. Its prime factorisation is
- 3
The divisors add up to 1026; without 490 itself that is 536, so 490 is abundant (536 is more than 490). Euler's totient φ(490) = 168 numbers up to 490 share no factor with it.
- 4
The digits of 490 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 22 steps to reach 1.
LaTeX source of the formulas on this page
\[ 490 = 2 \times 5 \times 7^{2} \]490 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 1026 |
| Euler totient φ(n) | 168 |
| Square | 240100 |
| Cube | 117649000 |
| Square root | 22.135944 (= 7√10) |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 22 |
| Scientific notation | 4.9 × |
490 in other forms
| Form | Value |
|---|---|
| In words | four hundred and ninety |
| Roman numerals | CDXC |
| Binary (base 2) | 111101010 |
| Octal (base 8) | 752 |
| Hexadecimal (base 16) | 1EA |
| Base 3 | 200011 |
| As time | 490 seconds = 8 min 10 s |
Is 490 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (490 ÷ 2 = 245) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 1) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (490 ÷ 5 = 98) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (490 ÷ 7 = 70) | 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 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 4) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (490 ÷ 10 = 49) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 10) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 490 a prime number?
No. 490 = 2 × 5 × , so it is divisible by 2.
What are the factors of 490?
1, 2, 5, 7, 10, 14, 35, 49, 70, 98, 245, 490.
What is 490 in binary?
111101010 (hexadecimal 1EA, octal 752).
What is the square root of 490?
About 22.1359, exactly 7√10.
What is 490 in Roman numerals?
CDXC.
Is 490 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 490?
490 is a happy number: repeatedly adding the squares of its digits reaches 1.