The number 21152
21152 is a composite number with 12 divisors. Its prime factorisation is × 661. Divisors (12): 1, 2, 4, 8, 16, 32, 661, 1322, 2644, 5288, 10576, 21152.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
21152 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
21152 is composite. Its prime factorisation is
- 3
The divisors add up to 41706; without 21152 itself that is 20554, so 21152 is deficient (20554 is less than 21152). Euler's totient φ(21152) = 10560 numbers up to 21152 share no factor with it.
- 4
The digits of 21152 add up to 11, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 118 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21152 = 2^{5} \times 661 \]21152 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 41706 |
| Euler totient φ(n) | 10560 |
| Square | 447407104 |
| Cube | 9463555063808 |
| Square root | 145.437272 (= 4√1322) |
| Digit sum / digital root | 11 / 2 |
| Collatz steps to 1 | 118 |
| Scientific notation | 2.1152 × |
21152 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand one hundred and fifty-two |
| Binary (base 2) | 101001010100000 |
| Octal (base 8) | 51240 |
| Hexadecimal (base 16) | 52A0 |
| Base 3 | 1002000102 |
| As time | 21152 seconds = 5 h 52 min 32 s |
Is 21152 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21152 ÷ 2 = 10576) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 2) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (21152 ÷ 4 = 5288) | 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 2) | 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 (21152 ÷ 8 = 2644) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | 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 10) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21152 a prime number?
No. 21152 = × 661, so it is divisible by 2.
What are the factors of 21152?
1, 2, 4, 8, 16, 32, 661, 1322, 2644, 5288, 10576, 21152.
What is 21152 in binary?
101001010100000 (hexadecimal 52A0, octal 51240).
What is the square root of 21152?
About 145.4373, exactly 4√1322.
Is 21152 divisible by 3?
No. Its digits add up to 11, which is not a multiple of 3.
What is special about the number 21152?
It is a composite number with 12 divisors.