The number 747
747 is a palindrome: it reads 747 backwards too. Its prime factorisation is × 83. Divisors (6): 1, 3, 9, 83, 249, 747.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 747: a palindrome: it reads 747 backwards too.
- 2
747 is composite. Its prime factorisation is
- 3
The divisors add up to 1092; without 747 itself that is 345, so 747 is deficient (345 is less than 747). Euler's totient φ(747) = 492 numbers up to 747 share no factor with it.
- 4
The digits of 747 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 46 steps to reach 1.
LaTeX source of the formulas on this page
\[ 747 = 3^{2} \times 83 \]747 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 1092 |
| Euler totient φ(n) | 492 |
| Square | 558009 |
| Cube | 416832723 |
| Square root | 27.331301 (= 3√83) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 46 |
| Scientific notation | 7.47 × |
747 in other forms
| Form | Value |
|---|---|
| In words | seven hundred and forty-seven |
| Roman numerals | DCCXLVII |
| Binary (base 2) | 1011101011 |
| Octal (base 8) | 1353 |
| Hexadecimal (base 16) | 2EB |
| Base 3 | 1000200 |
| As time | 747 seconds = 12 min 27 s |
Is 747 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 (747 ÷ 3 = 249) | 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 | No (remainder 2) | 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (747 ÷ 9 = 83) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 7) | 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 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 747 a prime number?
No. 747 = × 83, so it is divisible by 3.
What are the factors of 747?
1, 3, 9, 83, 249, 747.
What is 747 in binary?
1011101011 (hexadecimal 2EB, octal 1353).
What is the square root of 747?
About 27.3313, exactly 3√83.
What is 747 in Roman numerals?
DCCXLVII.
Is 747 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 747?
747 is a palindrome: it reads 747 backwards too.