The number 71389
71389 is a twin prime (71387 and 71389 are both prime) and the 7070th prime number. Its only divisors are 1 and 71389.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 71389: a twin prime (71387 and 71389 are both prime); the 7070th prime number.
- 2
71389 is prime, so its only factors are 1 and 71389. It is the 7070th prime; the next prime is 71399 and the one before is 71387.
- 3
The divisors add up to 71390; without 71389 itself that is 1, so 71389 is deficient (1 is less than 71389). Euler's totient φ(71389) = 71388 numbers up to 71389 share no factor with it.
- 4
The digits of 71389 add up to 28, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 73 steps to reach 1.
71389 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 71390 |
| Euler totient φ(n) | 71388 |
| Square | 5096389321 |
| Cube | 363826137236869 |
| Square root | 267.187200 |
| Digit sum / digital root | 28 / 1 |
| Collatz steps to 1 | 73 |
| Scientific notation | 7.1389 × |
71389 in other forms
| Form | Value |
|---|---|
| In words | seventy-one thousand three hundred and eighty-nine |
| Binary (base 2) | 10001011011011101 |
| Octal (base 8) | 213335 |
| Hexadecimal (base 16) | 116DD |
| Base 3 | 10121221001 |
| As time | 71389 seconds = 19 h 49 min 49 s |
Is 71389 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 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | 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 10) | 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 71389 a prime number?
Yes. 71389 is divisible only by 1 and itself.
What are the factors of 71389?
1, 71389.
What is 71389 in binary?
10001011011011101 (hexadecimal 116DD, octal 213335).
What is the square root of 71389?
About 267.1872.
Is 71389 divisible by 3?
No. Its digits add up to 28, which is not a multiple of 3.
What is special about the number 71389?
71389 is a twin prime (71387 and 71389 are both prime); the 7070th prime number.