The number 495
495 is a binary palindrome (111101111). Its prime factorisation is × 5 × 11. Divisors (12): 1, 3, 5, 9, 11, 15, 33, 45, 55, 99, 165, 495.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 495: a binary palindrome (111101111).
- 2
495 is composite. Its prime factorisation is
- 3
The divisors add up to 936; without 495 itself that is 441, so 495 is deficient (441 is less than 495). Euler's totient φ(495) = 240 numbers up to 495 share no factor with it.
- 4
The digits of 495 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 97 steps to reach 1.
LaTeX source of the formulas on this page
\[ 495 = 3^{2} \times 5 \times 11 \]495 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 936 |
| Euler totient φ(n) | 240 |
| Square | 245025 |
| Cube | 121287375 |
| Square root | 22.248595 (= 3√55) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 97 |
| Scientific notation | 4.95 × |
495 in other forms
| Form | Value |
|---|---|
| In words | four hundred and ninety-five |
| Roman numerals | CDXCV |
| Binary (base 2) | 111101111 |
| Octal (base 8) | 757 |
| Hexadecimal (base 16) | 1EF |
| Base 3 | 200100 |
| As time | 495 seconds = 8 min 15 s |
Is 495 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 (495 ÷ 3 = 165) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (495 ÷ 5 = 99) | 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 5) | 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 7) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (495 ÷ 9 = 55) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (495 ÷ 11 = 45) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 495 a prime number?
No. 495 = × 5 × 11, so it is divisible by 3.
What are the factors of 495?
1, 3, 5, 9, 11, 15, 33, 45, 55, 99, 165, 495.
What is 495 in binary?
111101111 (hexadecimal 1EF, octal 757).
What is the square root of 495?
About 22.2486, exactly 3√55.
What is 495 in Roman numerals?
CDXCV.
Is 495 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 495?
495 is a binary palindrome (111101111).