The number 5381
5381 is the 709th prime number. Its only divisors are 1 and 5381.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 5381: the 709th prime number.
- 2
5381 is prime, so its only factors are 1 and 5381. It is the 709th prime; the next prime is 5387 and the one before is 5351.
- 3
The divisors add up to 5382; without 5381 itself that is 1, so 5381 is deficient (1 is less than 5381). Euler's totient φ(5381) = 5380 numbers up to 5381 share no factor with it.
- 4
The digits of 5381 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 116 steps to reach 1.
5381 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 5382 |
| Euler totient φ(n) | 5380 |
| Square | 28955161 |
| Cube | 155807721341 |
| Square root | 73.355300 |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 116 |
| Scientific notation | 5.381 × |
5381 in other forms
| Form | Value |
|---|---|
| In words | five thousand three hundred and eighty-one |
| Binary (base 2) | 1010100000101 |
| Octal (base 8) | 12405 |
| Hexadecimal (base 16) | 1505 |
| Base 3 | 21101022 |
| As time | 5381 seconds = 1 h 29 min 41 s |
Is 5381 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 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | 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 5) | 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 8) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 5381 a prime number?
Yes. 5381 is divisible only by 1 and itself.
What are the factors of 5381?
1, 5381.
What is 5381 in binary?
1010100000101 (hexadecimal 1505, octal 12405).
What is the square root of 5381?
About 73.3553.
Is 5381 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 5381?
5381 is the 709th prime number.