The number 47947
47947 is the 4941st prime number. Its only divisors are 1 and 47947.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 47947: the 4941st prime number.
- 2
47947 is prime, so its only factors are 1 and 47947. It is the 4941st prime; the next prime is 47951 and the one before is 47939.
- 3
The divisors add up to 47948; without 47947 itself that is 1, so 47947 is deficient (1 is less than 47947). Euler's totient φ(47947) = 47946 numbers up to 47947 share no factor with it.
- 4
The digits of 47947 add up to 31, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 83 steps to reach 1.
47947 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 47948 |
| Euler totient φ(n) | 47946 |
| Square | 2298914809 |
| Cube | 110226068347123 |
| Square root | 218.968034 |
| Digit sum / digital root | 31 / 4 |
| Collatz steps to 1 | 83 |
| Scientific notation | 4.7947 × |
47947 in other forms
| Form | Value |
|---|---|
| In words | forty-seven thousand nine hundred and forty-seven |
| Binary (base 2) | 1011101101001011 |
| Octal (base 8) | 135513 |
| Hexadecimal (base 16) | BB4B |
| Base 3 | 2102202211 |
| As time | 47947 seconds = 13 h 19 min 7 s |
Is 47947 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 1) | 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 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 4) | 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 | No (remainder 4) | 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 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 7) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 47947 a prime number?
Yes. 47947 is divisible only by 1 and itself.
What are the factors of 47947?
1, 47947.
What is 47947 in binary?
1011101101001011 (hexadecimal BB4B, octal 135513).
What is the square root of 47947?
About 218.9680.
Is 47947 divisible by 3?
No. Its digits add up to 31, which is not a multiple of 3.
What is special about the number 47947?
47947 is the 4941st prime number.