The number 13381
13381 is the 1587th prime number. Its only divisors are 1 and 13381.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 13381: the 1587th prime number.
- 2
13381 is prime, so its only factors are 1 and 13381. It is the 1587th prime; the next prime is 13397 and the one before is 13367.
- 3
The divisors add up to 13382; without 13381 itself that is 1, so 13381 is deficient (1 is less than 13381). Euler's totient φ(13381) = 13380 numbers up to 13381 share no factor with it.
- 4
The digits of 13381 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 138 steps to reach 1.
13381 at a glance
| Property | Value |
|---|---|
| Type | prime |
| Number of divisors | 2 |
| Sum of divisors | 13382 |
| Euler totient φ(n) | 13380 |
| Square | 179051161 |
| Cube | 2395883585341 |
| Square root | 115.676272 |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 138 |
| Scientific notation | 1.3381 × |
13381 in other forms
| Form | Value |
|---|---|
| In words | thirteen thousand three hundred and eighty-one |
| Binary (base 2) | 11010001000101 |
| Octal (base 8) | 32105 |
| Hexadecimal (base 16) | 3445 |
| Base 3 | 200100121 |
| As time | 13381 seconds = 3 h 43 min 1 s |
Is 13381 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 1) | 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | 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 5) | 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 13381 a prime number?
Yes. 13381 is divisible only by 1 and itself.
What are the factors of 13381?
1, 13381.
What is 13381 in binary?
11010001000101 (hexadecimal 3445, octal 32105).
What is the square root of 13381?
About 115.6763.
Is 13381 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 13381?
13381 is the 1587th prime number.