The number 7938
7938 is a composite number with 30 divisors. Its prime factorisation is 2 × × . Divisors (30): 1, 2, 3, 6, 7, 9, 14, 18, 21, 27, 42, 49, 54, 63, 81, 98 … 7938.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 7938: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 27.
- 2
7938 is composite. Its prime factorisation is
- 3
The divisors add up to 20691; without 7938 itself that is 12753, so 7938 is abundant (12753 is more than 7938). Euler's totient φ(7938) = 2268 numbers up to 7938 share no factor with it.
- 4
The digits of 7938 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 145 steps to reach 1.
LaTeX source of the formulas on this page
\[ 7938 = 2 \times 3^{4} \times 7^{2} \]7938 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 30 |
| Sum of divisors | 20691 |
| Euler totient φ(n) | 2268 |
| Square | 63011844 |
| Cube | 500188017672 |
| Square root | 89.095454 (= 63√2) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 145 |
| Scientific notation | 7.938 × |
7938 in other forms
| Form | Value |
|---|---|
| In words | seven thousand nine hundred and thirty-eight |
| Binary (base 2) | 1111100000010 |
| Octal (base 8) | 17402 |
| Hexadecimal (base 16) | 1F02 |
| Base 3 | 101220000 |
| As time | 7938 seconds = 2 h 12 min 18 s |
Is 7938 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (7938 ÷ 2 = 3969) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (7938 ÷ 3 = 2646) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (7938 ÷ 6 = 1323) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (7938 ÷ 7 = 1134) | 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 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (7938 ÷ 9 = 882) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 8) | 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 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 7938 a prime number?
No. 7938 = 2 × × , so it is divisible by 2.
What are the factors of 7938?
1, 2, 3, 6, 7, 9, 14, 18, 21, 27, 42, 49, 54, 63, 81, 98, 126, 147, 162, 189, 294, 378, 441, 567, 882, 1134, 1323, 2646, 3969, 7938.
What is 7938 in binary?
1111100000010 (hexadecimal 1F02, octal 17402).
What is the square root of 7938?
About 89.0955, exactly 63√2.
Is 7938 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 7938?
7938 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 27.