The number 939
939 is a palindrome: it reads 939 backwards too. Its prime factorisation is 3 × 313. Divisors (4): 1, 3, 313, 939.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 939: a palindrome: it reads 939 backwards too; a semiprime: 3 × 313, the product of two primes.
- 2
939 is composite. Its prime factorisation is
- 3
The divisors add up to 1256; without 939 itself that is 317, so 939 is deficient (317 is less than 939). Euler's totient φ(939) = 624 numbers up to 939 share no factor with it.
- 4
The digits of 939 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 85 steps to reach 1.
LaTeX source of the formulas on this page
\[ 939 = 3 \times 313 \]
939 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 1256 |
| Euler totient φ(n) | 624 |
| Square | 881721 |
| Cube | 827936019 |
| Square root | 30.643107 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 85 |
| Scientific notation | 9.39 × |
939 in other forms
| Form | Value |
|---|---|
| In words | nine hundred and thirty-nine |
| Roman numerals | CMXXXIX |
| Binary (base 2) | 1110101011 |
| Octal (base 8) | 1653 |
| Hexadecimal (base 16) | 3AB |
| Base 3 | 1021210 |
| As time | 939 seconds = 15 min 39 s |
Is 939 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 (939 ÷ 3 = 313) | 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 | No (remainder 1) | 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | 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 4) | 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 939 a prime number?
No. 939 = 3 × 313, so it is divisible by 3.
What are the factors of 939?
1, 3, 313, 939.
What is 939 in binary?
1110101011 (hexadecimal 3AB, octal 1653).
What is the square root of 939?
About 30.6431.
What is 939 in Roman numerals?
CMXXXIX.
Is 939 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 939?
939 is a palindrome: it reads 939 backwards too; a semiprime: 3 × 313, the product of two primes.