The number 27988
27988 is a composite number with 6 divisors. Its prime factorisation is × 6997. Divisors (6): 1, 2, 4, 6997, 13994, 27988.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 27988: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
27988 is composite. Its prime factorisation is
- 3
The divisors add up to 48986; without 27988 itself that is 20998, so 27988 is deficient (20998 is less than 27988). Euler's totient φ(27988) = 13992 numbers up to 27988 share no factor with it.
- 4
The digits of 27988 add up to 34, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 121 steps to reach 1.
LaTeX source of the formulas on this page
\[ 27988 = 2^{2} \times 6997 \]27988 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 48986 |
| Euler totient φ(n) | 13992 |
| Square | 783328144 |
| Cube | 21923788094272 |
| Square root | 167.296145 (= 2√6997) |
| Digit sum / digital root | 34 / 7 |
| Collatz steps to 1 | 121 |
| Scientific notation | 2.7988 × |
27988 in other forms
| Form | Value |
|---|---|
| In words | twenty-seven thousand nine hundred and eighty-eight |
| Binary (base 2) | 110110101010100 |
| Octal (base 8) | 66524 |
| Hexadecimal (base 16) | 6D54 |
| Base 3 | 1102101121 |
| As time | 27988 seconds = 7 h 46 min 28 s |
Is 27988 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (27988 ÷ 2 = 13994) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 1) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (27988 ÷ 4 = 6997) | 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 | No (remainder 4) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | 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 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 27988 a prime number?
No. 27988 = × 6997, so it is divisible by 2.
What are the factors of 27988?
1, 2, 4, 6997, 13994, 27988.
What is 27988 in binary?
110110101010100 (hexadecimal 6D54, octal 66524).
What is the square root of 27988?
About 167.2961, exactly 2√6997.
Is 27988 divisible by 3?
No. Its digits add up to 34, which is not a multiple of 3.
What is special about the number 27988?
27988 is a happy number: repeatedly adding the squares of its digits reaches 1.