The number 20984
20984 is a composite number with 16 divisors. Its prime factorisation is × 43 × 61. Divisors (16): 1, 2, 4, 8, 43, 61, 86, 122, 172, 244, 344, 488, 2623, 5246, 10492, 20984.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
20984 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
20984 is composite. Its prime factorisation is
- 3
The divisors add up to 40920; without 20984 itself that is 19936, so 20984 is deficient (19936 is less than 20984). Euler's totient φ(20984) = 10080 numbers up to 20984 share no factor with it.
- 4
The digits of 20984 add up to 23, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 105 steps to reach 1.
LaTeX source of the formulas on this page
\[ 20984 = 2^{3} \times 43 \times 61 \]20984 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 40920 |
| Euler totient φ(n) | 10080 |
| Square | 440328256 |
| Cube | 9239848123904 |
| Square root | 144.858552 (= 2√5246) |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 105 |
| Scientific notation | 2.0984 × |
20984 in other forms
| Form | Value |
|---|---|
| In words | twenty thousand nine hundred and eighty-four |
| Binary (base 2) | 101000111111000 |
| Octal (base 8) | 50770 |
| Hexadecimal (base 16) | 51F8 |
| Base 3 | 1001210012 |
| As time | 20984 seconds = 5 h 49 min 44 s |
Is 20984 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (20984 ÷ 2 = 10492) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (20984 ÷ 4 = 5246) | 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 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 | Yes (20984 ÷ 8 = 2623) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 4) | 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 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 20984 a prime number?
No. 20984 = × 43 × 61, so it is divisible by 2.
What are the factors of 20984?
1, 2, 4, 8, 43, 61, 86, 122, 172, 244, 344, 488, 2623, 5246, 10492, 20984.
What is 20984 in binary?
101000111111000 (hexadecimal 51F8, octal 50770).
What is the square root of 20984?
About 144.8586, exactly 2√5246.
Is 20984 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 20984?
It is a composite number with 16 divisors.