The number 21426
21426 is a composite number with 8 divisors. Its prime factorisation is 2 × 3 × 3571. Divisors (8): 1, 2, 3, 6, 3571, 7142, 10713, 21426.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
21426 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
21426 is composite. Its prime factorisation is
- 3
The divisors add up to 42864; without 21426 itself that is 21438, so 21426 is abundant (21438 is more than 21426). Euler's totient φ(21426) = 7140 numbers up to 21426 share no factor with it.
- 4
The digits of 21426 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 30 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21426 = 2 \times 3 \times 3571 \]
21426 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 42864 |
| Euler totient φ(n) | 7140 |
| Square | 459073476 |
| Cube | 9836108296776 |
| Square root | 146.376228 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 30 |
| Scientific notation | 2.1426 × |
21426 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand four hundred and twenty-six |
| Binary (base 2) | 101001110110010 |
| Octal (base 8) | 51662 |
| Hexadecimal (base 16) | 53B2 |
| Base 3 | 1002101120 |
| As time | 21426 seconds = 5 h 57 min 6 s |
Is 21426 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21426 ÷ 2 = 10713) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (21426 ÷ 3 = 7142) | 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 | No (remainder 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (21426 ÷ 6 = 3571) | 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 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 6) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 6) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 9) | 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 21426 a prime number?
No. 21426 = 2 × 3 × 3571, so it is divisible by 2.
What are the factors of 21426?
1, 2, 3, 6, 3571, 7142, 10713, 21426.
What is 21426 in binary?
101001110110010 (hexadecimal 53B2, octal 51662).
What is the square root of 21426?
About 146.3762.
Is 21426 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 21426?
It is a composite number with 8 divisors.