The number 47389
47389 is a twin prime (47387 and 47389 are both prime) and the 4887th prime number. Its only divisors are 1 and 47389.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 47389: a twin prime (47387 and 47389 are both prime); the 4887th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
47389 is prime, so its only factors are 1 and 47389. It is the 4887th prime; the next prime is 47407 and the one before is 47387.
- 3
The divisors add up to 47390; without 47389 itself that is 1, so 47389 is deficient (1 is less than 47389). Euler's totient φ(47389) = 47388 numbers up to 47389 share no factor with it.
- 4
The digits of 47389 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 75 steps to reach 1.
47389 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 47390 |
| Euler totient φ(n) | 47388 |
| Square | 2245717321 |
| Cube | 106422298124869 |
| Square root | 217.690147 |
| Digit sum / digital root | 31 / 4 |
| Collatz steps to 1 | 75 |
| Scientific notation | 4.7389 × |
47389 in other forms
| Form | Value |
|---|---|
| In words | forty-seven thousand three hundred and eighty-nine |
| Binary (base 2) | 1011100100011101 |
| Octal (base 8) | 134435 |
| Hexadecimal (base 16) | B91D |
| Base 3 | 2102000011 |
| As time | 47389 seconds = 13 h 9 min 49 s |
Is 47389 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 1) | 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 1) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 6) | 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 5) | 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 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 1) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 47389 a prime number?
Yes. 47389 is divisible only by 1 and itself.
What are the factors of 47389?
1, 47389.
What is 47389 in binary?
1011100100011101 (hexadecimal B91D, octal 134435).
What is the square root of 47389?
About 217.6901.
Is 47389 divisible by 3?
No. Its digits add up to 31, which is not a multiple of 3.
What is special about the number 47389?
47389 is a twin prime (47387 and 47389 are both prime); the 4887th prime number; a happy number: repeatedly adding the squares of its digits reaches 1.