The number 21064
21064 is a composite number with 8 divisors. Its prime factorisation is × 2633. Divisors (8): 1, 2, 4, 8, 2633, 5266, 10532, 21064.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
21064 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
21064 is composite. Its prime factorisation is
- 3
The divisors add up to 39510; without 21064 itself that is 18446, so 21064 is deficient (18446 is less than 21064). Euler's totient φ(21064) = 10528 numbers up to 21064 share no factor with it.
- 4
The digits of 21064 add up to 13, and repeating that until one digit is left gives the digital root 4. The Collatz sequence (halve if even, else 3n+1) takes 43 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21064 = 2^{3} \times 2633 \]21064 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 39510 |
| Euler totient φ(n) | 10528 |
| Square | 443692096 |
| Cube | 9345930310144 |
| Square root | 145.134420 (= 2√5266) |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 43 |
| Scientific notation | 2.1064 × |
21064 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand and sixty-four |
| Binary (base 2) | 101001001001000 |
| Octal (base 8) | 51110 |
| Hexadecimal (base 16) | 5248 |
| Base 3 | 1001220011 |
| As time | 21064 seconds = 5 h 51 min 4 s |
Is 21064 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21064 ÷ 2 = 10532) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 1) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (21064 ÷ 4 = 5266) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 4) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 (21064 ÷ 8 = 2633) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 4) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 4) | 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 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21064 a prime number?
No. 21064 = × 2633, so it is divisible by 2.
What are the factors of 21064?
1, 2, 4, 8, 2633, 5266, 10532, 21064.
What is 21064 in binary?
101001001001000 (hexadecimal 5248, octal 51110).
What is the square root of 21064?
About 145.1344, exactly 2√5266.
Is 21064 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 21064?
It is a composite number with 8 divisors.