The number 20988
20988 is a composite number with 36 divisors. Its prime factorisation is × × 11 × 53. Divisors (36): 1, 2, 3, 4, 6, 9, 11, 12, 18, 22, 33, 36, 44, 53, 66, 99 … 20988.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
20988 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
20988 is composite. Its prime factorisation is
- 3
The divisors add up to 58968; without 20988 itself that is 37980, so 20988 is abundant (37980 is more than 20988). Euler's totient φ(20988) = 6240 numbers up to 20988 share no factor with it.
- 4
The digits of 20988 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 87 steps to reach 1.
LaTeX source of the formulas on this page
\[ 20988 = 2^{2} \times 3^{2} \times 11 \times 53 \]20988 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 36 |
| Sum of divisors | 58968 |
| Euler totient φ(n) | 6240 |
| Square | 440496144 |
| Cube | 9245133070272 |
| Square root | 144.872358 (= 6√583) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 87 |
| Scientific notation | 2.0988 × |
20988 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand nine hundred and eighty-eight |
| Binary (base 2) | 101000111111100 |
| Octal (base 8) | 50774 |
| Hexadecimal (base 16) | 51FC |
| Base 3 | 1001210100 |
| As time | 20988 seconds = 5 h 49 min 48 s |
Is 20988 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (20988 ÷ 2 = 10494) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (20988 ÷ 3 = 6996) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (20988 ÷ 4 = 5247) | 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 (20988 ÷ 6 = 3498) | 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 | Yes (20988 ÷ 9 = 2332) | 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 | Yes (20988 ÷ 11 = 1908) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (20988 ÷ 12 = 1749) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 20988 a prime number?
No. 20988 = × × 11 × 53, so it is divisible by 2.
What are the factors of 20988?
1, 2, 3, 4, 6, 9, 11, 12, 18, 22, 33, 36, 44, 53, 66, 99, 106, 132, 159, 198, 212, 318, 396, 477, 583, 636, 954, 1166, 1749, 1908, 2332, 3498, 5247, 6996, 10494, 20988.
What is 20988 in binary?
101000111111100 (hexadecimal 51FC, octal 50774).
What is the square root of 20988?
About 144.8724, exactly 6√583.
Is 20988 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 20988?
It is a composite number with 36 divisors.