The number 1239
1239 is a composite number with 8 divisors. Its prime factorisation is 3 × 7 × 59. Divisors (8): 1, 3, 7, 21, 59, 177, 413, 1239.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
1239 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
1239 is composite. Its prime factorisation is
- 3
The divisors add up to 1920; without 1239 itself that is 681, so 1239 is deficient (681 is less than 1239). Euler's totient φ(1239) = 696 numbers up to 1239 share no factor with it.
- 4
The digits of 1239 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 132 steps to reach 1.
LaTeX source of the formulas on this page
\[ 1239 = 3 \times 7 \times 59 \]
1239 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 1920 |
| Euler totient φ(n) | 696 |
| Square | 1535121 |
| Cube | 1902014919 |
| Square root | 35.199432 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 132 |
| Scientific notation | 1.239 × |
1239 in other forms
| Form | Value |
|---|---|
| In words | one thousand two hundred and thirty-nine |
| Roman numerals | MCCXXXIX |
| Binary (base 2) | 10011010111 |
| Octal (base 8) | 2327 |
| Hexadecimal (base 16) | 4D7 |
| Base 3 | 1200220 |
| As time | 1239 seconds = 20 min 39 s |
Is 1239 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 (1239 ÷ 3 = 413) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | 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 (1239 ÷ 7 = 177) | 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 7) | 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 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 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 1239 a prime number?
No. 1239 = 3 × 7 × 59, so it is divisible by 3.
What are the factors of 1239?
1, 3, 7, 21, 59, 177, 413, 1239.
What is 1239 in binary?
10011010111 (hexadecimal 4D7, octal 2327).
What is the square root of 1239?
About 35.1994.
What is 1239 in Roman numerals?
MCCXXXIX.
Is 1239 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 1239?
It is a composite number with 8 divisors.