The number 1247
1247 is a composite number with 4 divisors. Its prime factorisation is 29 × 43. Divisors (4): 1, 29, 43, 1247.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 1247: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 29 × 43, the product of two primes.
- 2
1247 is composite. Its prime factorisation is
- 3
The divisors add up to 1320; without 1247 itself that is 73, so 1247 is deficient (73 is less than 1247). Euler's totient φ(1247) = 1176 numbers up to 1247 share no factor with it.
- 4
The digits of 1247 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 132 steps to reach 1.
LaTeX source of the formulas on this page
\[ 1247 = 29 \times 43 \]
1247 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 1320 |
| Euler totient φ(n) | 1176 |
| Square | 1555009 |
| Cube | 1939096223 |
| Square root | 35.312887 |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 132 |
| Scientific notation | 1.247 × |
1247 in other forms
| Form | Value |
|---|---|
| In words | one thousand two hundred and forty-seven |
| Roman numerals | MCCXLVII |
| Binary (base 2) | 10011011111 |
| Octal (base 8) | 2337 |
| Hexadecimal (base 16) | 4DF |
| Base 3 | 1201012 |
| As time | 1247 seconds = 20 min 47 s |
Is 1247 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 | No (remainder 2) | 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 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 | No (remainder 5) | 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 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 1247 a prime number?
No. 1247 = 29 × 43, so it is divisible by 29.
What are the factors of 1247?
1, 29, 43, 1247.
What is 1247 in binary?
10011011111 (hexadecimal 4DF, octal 2337).
What is the square root of 1247?
About 35.3129.
What is 1247 in Roman numerals?
MCCXLVII.
Is 1247 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 1247?
1247 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 29 × 43, the product of two primes.