The number 21270
21270 is a composite number with 16 divisors. Its prime factorisation is 2 × 3 × 5 × 709. Divisors (16): 1, 2, 3, 5, 6, 10, 15, 30, 709, 1418, 2127, 3545, 4254, 7090, 10635, 21270.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
21270 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
21270 is composite. Its prime factorisation is
- 3
The divisors add up to 51120; without 21270 itself that is 29850, so 21270 is abundant (29850 is more than 21270). Euler's totient φ(21270) = 5664 numbers up to 21270 share no factor with it.
- 4
The digits of 21270 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 56 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21270 = 2 \times 3 \times 5 \times 709 \]
21270 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 51120 |
| Euler totient φ(n) | 5664 |
| Square | 452412900 |
| Cube | 9622822383000 |
| Square root | 145.842381 |
| Digit sum / digital root | 12 / 3 |
| Collatz steps to 1 | 56 |
| Scientific notation | 2.127 × |
21270 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand two hundred and seventy |
| Binary (base 2) | 101001100010110 |
| Octal (base 8) | 51426 |
| Hexadecimal (base 16) | 5316 |
| Base 3 | 1002011210 |
| As time | 21270 seconds = 5 h 54 min 30 s |
Is 21270 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21270 ÷ 2 = 10635) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (21270 ÷ 3 = 7090) | 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 (21270 ÷ 5 = 4254) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (21270 ÷ 6 = 3545) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 4) | 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 6) | 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 (21270 ÷ 10 = 2127) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | 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 21270 a prime number?
No. 21270 = 2 × 3 × 5 × 709, so it is divisible by 2.
What are the factors of 21270?
1, 2, 3, 5, 6, 10, 15, 30, 709, 1418, 2127, 3545, 4254, 7090, 10635, 21270.
What is 21270 in binary?
101001100010110 (hexadecimal 5316, octal 51426).
What is the square root of 21270?
About 145.8424.
Is 21270 divisible by 3?
Yes. Its digits add up to 12, a multiple of 3.
What is special about the number 21270?
It is a composite number with 16 divisors.