The number 21432
21432 is a composite number with 32 divisors. Its prime factorisation is × 3 × 19 × 47. Divisors (32): 1, 2, 3, 4, 6, 8, 12, 19, 24, 38, 47, 57, 76, 94, 114, 141 … 21432.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21432: a Harshad number: divisible by its digit sum 12.
- 2
21432 is composite. Its prime factorisation is
- 3
The divisors add up to 57600; without 21432 itself that is 36168, so 21432 is abundant (36168 is more than 21432). Euler's totient φ(21432) = 6624 numbers up to 21432 share no factor with it.
- 4
The digits of 21432 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
\[ 21432 = 2^{3} \times 3 \times 19 \times 47 \]21432 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 57600 |
| Euler totient φ(n) | 6624 |
| Square | 459330624 |
| Cube | 9844373933568 |
| Square root | 146.396721 (= 2√5358) |
| Digit sum / digital root | 12 / 3 |
| Collatz steps to 1 | 30 |
| Scientific notation | 2.1432 × |
21432 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand four hundred and thirty-two |
| Binary (base 2) | 101001110111000 |
| Octal (base 8) | 51670 |
| Hexadecimal (base 16) | 53B8 |
| Base 3 | 1002101210 |
| As time | 21432 seconds = 5 h 57 min 12 s |
Is 21432 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21432 ÷ 2 = 10716) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (21432 ÷ 3 = 7144) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (21432 ÷ 4 = 5358) | 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 | Yes (21432 ÷ 6 = 3572) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 | Yes (21432 ÷ 8 = 2679) | 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 2) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (21432 ÷ 12 = 1786) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21432 a prime number?
No. 21432 = × 3 × 19 × 47, so it is divisible by 2.
What are the factors of 21432?
1, 2, 3, 4, 6, 8, 12, 19, 24, 38, 47, 57, 76, 94, 114, 141, 152, 188, 228, 282, 376, 456, 564, 893, 1128, 1786, 2679, 3572, 5358, 7144, 10716, 21432.
What is 21432 in binary?
101001110111000 (hexadecimal 53B8, octal 51670).
What is the square root of 21432?
About 146.3967, exactly 2√5358.
Is 21432 divisible by 3?
Yes. Its digits add up to 12, a multiple of 3.
What is special about the number 21432?
21432 is a Harshad number: divisible by its digit sum 12.