The number 21748
21748 is a composite number with 6 divisors. Its prime factorisation is × 5437. Divisors (6): 1, 2, 4, 5437, 10874, 21748.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
21748 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
21748 is composite. Its prime factorisation is
- 3
The divisors add up to 38066; without 21748 itself that is 16318, so 21748 is deficient (16318 is less than 21748). Euler's totient φ(21748) = 10872 numbers up to 21748 share no factor with it.
- 4
The digits of 21748 add up to 22, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 69 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21748 = 2^{2} \times 5437 \]21748 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 38066 |
| Euler totient φ(n) | 10872 |
| Square | 472975504 |
| Cube | 10286271260992 |
| Square root | 147.472031 (= 2√5437) |
| Digit sum / digital root | 22 / 4 |
| Collatz steps to 1 | 69 |
| Scientific notation | 2.1748 × |
21748 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand seven hundred and forty-eight |
| Binary (base 2) | 101010011110100 |
| Octal (base 8) | 52364 |
| Hexadecimal (base 16) | 54F4 |
| Base 3 | 1002211111 |
| As time | 21748 seconds = 6 h 2 min 28 s |
Is 21748 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21748 ÷ 2 = 10874) | 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 (21748 ÷ 4 = 5437) | 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 6) | 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 4) | 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 1) | 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 21748 a prime number?
No. 21748 = × 5437, so it is divisible by 2.
What are the factors of 21748?
1, 2, 4, 5437, 10874, 21748.
What is 21748 in binary?
101010011110100 (hexadecimal 54F4, octal 52364).
What is the square root of 21748?
About 147.4720, exactly 2√5437.
Is 21748 divisible by 3?
No. Its digits add up to 22, which is not a multiple of 3.
What is special about the number 21748?
It is a composite number with 6 divisors.