The number 47939
47939 is the 4940th prime number. Its only divisors are 1 and 47939.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 47939: the 4940th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
47939 is prime, so its only factors are 1 and 47939. It is the 4940th prime; the next prime is 47947 and the one before is 47933.
- 3
The divisors add up to 47940; without 47939 itself that is 1, so 47939 is deficient (1 is less than 47939). Euler's totient φ(47939) = 47938 numbers up to 47939 share no factor with it.
- 4
The digits of 47939 add up to 32, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 52 steps to reach 1.
47939 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 47940 |
| Euler totient φ(n) | 47938 |
| Square | 2298147721 |
| Cube | 110170903597019 |
| Square root | 218.949766 |
| Digit sum / digital root | 32 / 5 |
| Collatz steps to 1 | 52 |
| Scientific notation | 4.7939 × |
47939 in other forms
| Form | Value |
|---|---|
| In words | forty-seven thousand nine hundred and thirty-nine |
| Binary (base 2) | 1011101101000011 |
| Octal (base 8) | 135503 |
| Hexadecimal (base 16) | BB43 |
| Base 3 | 2102202112 |
| As time | 47939 seconds = 13 h 18 min 59 s |
Is 47939 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 4) | 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 3) | 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 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 9) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 1) | 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 47939 a prime number?
Yes. 47939 is divisible only by 1 and itself.
What are the factors of 47939?
1, 47939.
What is 47939 in binary?
1011101101000011 (hexadecimal BB43, octal 135503).
What is the square root of 47939?
About 218.9498.
Is 47939 divisible by 3?
No. Its digits add up to 32, which is not a multiple of 3.
What is special about the number 47939?
47939 is the 4940th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.