The number 21027
21027 is a composite number with 8 divisors. Its prime factorisation is 3 × 43 × 163. Divisors (8): 1, 3, 43, 129, 163, 489, 7009, 21027.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
21027 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
21027 is composite. Its prime factorisation is
- 3
The divisors add up to 28864; without 21027 itself that is 7837, so 21027 is deficient (7837 is less than 21027). Euler's totient φ(21027) = 13608 numbers up to 21027 share no factor with it.
- 4
The digits of 21027 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 30 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21027 = 3 \times 43 \times 163 \]
21027 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 28864 |
| Euler totient φ(n) | 13608 |
| Square | 442134729 |
| Cube | 9296766946683 |
| Square root | 145.006896 |
| Digit sum / digital root | 12 / 3 |
| Collatz steps to 1 | 30 |
| Scientific notation | 2.1027 × |
21027 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand and twenty-seven |
| Binary (base 2) | 101001000100011 |
| Octal (base 8) | 51043 |
| Hexadecimal (base 16) | 5223 |
| Base 3 | 1001211210 |
| As time | 21027 seconds = 5 h 50 min 27 s |
Is 21027 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 (21027 ÷ 3 = 7009) | 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 2) | 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 | 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 3) | 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 | No (remainder 7) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 6) | 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 21027 a prime number?
No. 21027 = 3 × 43 × 163, so it is divisible by 3.
What are the factors of 21027?
1, 3, 43, 129, 163, 489, 7009, 21027.
What is 21027 in binary?
101001000100011 (hexadecimal 5223, octal 51043).
What is the square root of 21027?
About 145.0069.
Is 21027 divisible by 3?
Yes. Its digits add up to 12, a multiple of 3.
What is special about the number 21027?
It is a composite number with 8 divisors.