The number 21641
21641 is a composite number with 8 divisors. Its prime factorisation is 17 × 19 × 67. Divisors (8): 1, 17, 19, 67, 323, 1139, 1273, 21641.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
21641 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
21641 is composite. Its prime factorisation is
- 3
The divisors add up to 24480; without 21641 itself that is 2839, so 21641 is deficient (2839 is less than 21641). Euler's totient φ(21641) = 19008 numbers up to 21641 share no factor with it.
- 4
The digits of 21641 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 193 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21641 = 17 \times 19 \times 67 \]
21641 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 24480 |
| Euler totient φ(n) | 19008 |
| Square | 468332881 |
| Cube | 10135191877721 |
| Square root | 147.108803 |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 193 |
| Scientific notation | 2.1641 × |
21641 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand six hundred and forty-one |
| Binary (base 2) | 101010010001001 |
| Octal (base 8) | 52211 |
| Hexadecimal (base 16) | 5489 |
| Base 3 | 1002200112 |
| As time | 21641 seconds = 6 h 0 min 41 s |
Is 21641 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | 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 | No (remainder 1) | 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 | No (remainder 5) | 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 1) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 1) | 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 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21641 a prime number?
No. 21641 = 17 × 19 × 67, so it is divisible by 17.
What are the factors of 21641?
1, 17, 19, 67, 323, 1139, 1273, 21641.
What is 21641 in binary?
101010010001001 (hexadecimal 5489, octal 52211).
What is the square root of 21641?
About 147.1088.
Is 21641 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 21641?
It is a composite number with 8 divisors.