The number 12789
12789 is a composite number with 18 divisors. Its prime factorisation is × × 29. Divisors (18): 1, 3, 7, 9, 21, 29, 49, 63, 87, 147, 203, 261, 441, 609, 1421, 1827 … 12789.
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How to work it out
- 1
12789 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
12789 is composite. Its prime factorisation is
- 3
The divisors add up to 22230; without 12789 itself that is 9441, so 12789 is deficient (9441 is less than 12789). Euler's totient φ(12789) = 7056 numbers up to 12789 share no factor with it.
- 4
The digits of 12789 add up to 27, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 76 steps to reach 1.
LaTeX source of the formulas on this page
\[ 12789 = 3^{2} \times 7^{2} \times 29 \]12789 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 18 |
| Sum of divisors | 22230 |
| Euler totient φ(n) | 7056 |
| Square | 163558521 |
| Cube | 2091749925069 |
| Square root | 113.088461 (= 21√29) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 76 |
| Scientific notation | 1.2789 × |
12789 in other forms
| Form | Value |
|---|---|
| In words | twelve thousand seven hundred and eighty-nine |
| Binary (base 2) | 11000111110101 |
| Octal (base 8) | 30765 |
| Hexadecimal (base 16) | 31F5 |
| Base 3 | 122112200 |
| As time | 12789 seconds = 3 h 33 min 9 s |
Is 12789 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 (12789 ÷ 3 = 4263) | 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 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (12789 ÷ 7 = 1827) | 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 | Yes (12789 ÷ 9 = 1421) | 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 7) | 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 12789 a prime number?
No. 12789 = × × 29, so it is divisible by 3.
What are the factors of 12789?
1, 3, 7, 9, 21, 29, 49, 63, 87, 147, 203, 261, 441, 609, 1421, 1827, 4263, 12789.
What is 12789 in binary?
11000111110101 (hexadecimal 31F5, octal 30765).
What is the square root of 12789?
About 113.0885, exactly 21√29.
Is 12789 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 12789?
It is a composite number with 18 divisors.