The number 21444
21444 is a composite number with 12 divisors. Its prime factorisation is × 3 × 1787. Divisors (12): 1, 2, 3, 4, 6, 12, 1787, 3574, 5361, 7148, 10722, 21444.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
21444 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
21444 is composite. Its prime factorisation is
- 3
The divisors add up to 50064; without 21444 itself that is 28620, so 21444 is abundant (28620 is more than 21444). Euler's totient φ(21444) = 7144 numbers up to 21444 share no factor with it.
- 4
The digits of 21444 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 74 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21444 = 2^{2} \times 3 \times 1787 \]21444 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 50064 |
| Euler totient φ(n) | 7144 |
| Square | 459845136 |
| Cube | 9860919096384 |
| Square root | 146.437700 (= 2√5361) |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 74 |
| Scientific notation | 2.1444 × |
21444 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand four hundred and forty-four |
| Binary (base 2) | 101001111000100 |
| Octal (base 8) | 51704 |
| Hexadecimal (base 16) | 53C4 |
| Base 3 | 1002102020 |
| As time | 21444 seconds = 5 h 57 min 24 s |
Is 21444 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21444 ÷ 2 = 10722) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (21444 ÷ 3 = 7148) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (21444 ÷ 4 = 5361) | 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 | Yes (21444 ÷ 6 = 3574) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | 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 6) | 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 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (21444 ÷ 12 = 1787) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21444 a prime number?
No. 21444 = × 3 × 1787, so it is divisible by 2.
What are the factors of 21444?
1, 2, 3, 4, 6, 12, 1787, 3574, 5361, 7148, 10722, 21444.
What is 21444 in binary?
101001111000100 (hexadecimal 53C4, octal 51704).
What is the square root of 21444?
About 146.4377, exactly 2√5361.
Is 21444 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 21444?
It is a composite number with 12 divisors.