The number 21483
21483 is a composite number with 24 divisors. Its prime factorisation is × 7 × 11 × 31. Divisors (24): 1, 3, 7, 9, 11, 21, 31, 33, 63, 77, 93, 99, 217, 231, 279, 341 … 21483.
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How to work it out
- 1
What is special about 21483: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
21483 is composite. Its prime factorisation is
- 3
The divisors add up to 39936; without 21483 itself that is 18453, so 21483 is deficient (18453 is less than 21483). Euler's totient φ(21483) = 10800 numbers up to 21483 share no factor with it.
- 4
The digits of 21483 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 100 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21483 = 3^{2} \times 7 \times 11 \times 31 \]21483 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 39936 |
| Euler totient φ(n) | 10800 |
| Square | 461519289 |
| Cube | 9914818885587 |
| Square root | 146.570802 (= 3√2387) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 100 |
| Scientific notation | 2.1483 × |
21483 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand four hundred and eighty-three |
| Binary (base 2) | 101001111101011 |
| Octal (base 8) | 51753 |
| Hexadecimal (base 16) | 53EB |
| Base 3 | 1002110200 |
| As time | 21483 seconds = 5 h 58 min 3 s |
Is 21483 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (21483 ÷ 3 = 7161) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | 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 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (21483 ÷ 7 = 3069) | 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (21483 ÷ 9 = 2387) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 3) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (21483 ÷ 11 = 1953) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21483 a prime number?
No. 21483 = × 7 × 11 × 31, so it is divisible by 3.
What are the factors of 21483?
1, 3, 7, 9, 11, 21, 31, 33, 63, 77, 93, 99, 217, 231, 279, 341, 651, 693, 1023, 1953, 2387, 3069, 7161, 21483.
What is 21483 in binary?
101001111101011 (hexadecimal 53EB, octal 51753).
What is the square root of 21483?
About 146.5708, exactly 3√2387.
Is 21483 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 21483?
21483 is a happy number: repeatedly adding the squares of its digits reaches 1.