The number 13281
13281 is a composite number with 8 divisors. Its prime factorisation is 3 × 19 × 233. Divisors (8): 1, 3, 19, 57, 233, 699, 4427, 13281.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 13281: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
13281 is composite. Its prime factorisation is
- 3
The divisors add up to 18720; without 13281 itself that is 5439, so 13281 is deficient (5439 is less than 13281). Euler's totient φ(13281) = 8352 numbers up to 13281 share no factor with it.
- 4
The digits of 13281 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 76 steps to reach 1.
LaTeX source of the formulas on this page
\[ 13281 = 3 \times 19 \times 233 \]
13281 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 18720 |
| Euler totient φ(n) | 8352 |
| Square | 176384961 |
| Cube | 2342568667041 |
| Square root | 115.243221 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 76 |
| Scientific notation | 1.3281 × |
13281 in other forms
| Form | Value |
|---|---|
| In words | thirteen thousand two hundred and eighty-one |
| Binary (base 2) | 11001111100001 |
| Octal (base 8) | 31741 |
| Hexadecimal (base 16) | 33E1 |
| Base 3 | 200012220 |
| As time | 13281 seconds = 3 h 41 min 21 s |
Is 13281 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 | Yes (13281 ÷ 3 = 4427) | 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 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 6) | 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 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 13281 a prime number?
No. 13281 = 3 × 19 × 233, so it is divisible by 3.
What are the factors of 13281?
1, 3, 19, 57, 233, 699, 4427, 13281.
What is 13281 in binary?
11001111100001 (hexadecimal 33E1, octal 31741).
What is the square root of 13281?
About 115.2432.
Is 13281 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 13281?
13281 is a happy number: repeatedly adding the squares of its digits reaches 1.