The number 21450
21450 is a composite number with 48 divisors. Its prime factorisation is 2 × 3 × × 11 × 13. Divisors (48): 1, 2, 3, 5, 6, 10, 11, 13, 15, 22, 25, 26, 30, 33, 39, 50 … 21450.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
21450 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
21450 is composite. Its prime factorisation is
- 3
The divisors add up to 62496; without 21450 itself that is 41046, so 21450 is abundant (41046 is more than 21450). Euler's totient φ(21450) = 4800 numbers up to 21450 share no factor with it.
- 4
The digits of 21450 add up to 12, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 48 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21450 = 2 \times 3 \times 5^{2} \times 11 \times 13 \]21450 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 48 |
| Sum of divisors | 62496 |
| Euler totient φ(n) | 4800 |
| Square | 460102500 |
| Cube | 9869198625000 |
| Square root | 146.458185 (= 5√858) |
| Digit sum / digital root | 12 / 3 |
| Collatz steps to 1 | 48 |
| Scientific notation | 2.145 × |
21450 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand four hundred and fifty |
| Binary (base 2) | 101001111001010 |
| Octal (base 8) | 51712 |
| Hexadecimal (base 16) | 53CA |
| Base 3 | 1002102110 |
| As time | 21450 seconds = 5 h 57 min 30 s |
Is 21450 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21450 ÷ 2 = 10725) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (21450 ÷ 3 = 7150) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (21450 ÷ 5 = 4290) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (21450 ÷ 6 = 3575) | 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 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (21450 ÷ 10 = 2145) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (21450 ÷ 11 = 1950) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21450 a prime number?
No. 21450 = 2 × 3 × × 11 × 13, so it is divisible by 2.
What are the factors of 21450?
1, 2, 3, 5, 6, 10, 11, 13, 15, 22, 25, 26, 30, 33, 39, 50, 55, 65, 66, 75, 78, 110, 130, 143, 150, 165, 195, 275, 286, 325, 330, 390, 429, 550, 650, 715, 825, 858, 975, 1430, 1650, 1950, 2145, 3575, 4290, 7150, 10725, 21450.
What is 21450 in binary?
101001111001010 (hexadecimal 53CA, octal 51712).
What is the square root of 21450?
About 146.4582, exactly 5√858.
Is 21450 divisible by 3?
Yes. Its digits add up to 12, a multiple of 3.
What is special about the number 21450?
It is a composite number with 48 divisors.