The number 12221
12221 is a palindrome: it reads 12221 backwards too. Its prime factorisation is Ć 101. Divisors (6): 1, 11, 101, 121, 1111, 12221.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 12221: a palindrome: it reads 12221 backwards too.
- 2
12221 is composite. Its prime factorisation is
- 3
The divisors add up to 13566; without 12221 itself that is 1345, so 12221 is deficient (1345 is less than 12221). Euler's totient Ļ(12221) = 11000 numbers up to 12221 share no factor with it.
- 4
The digits of 12221 add up to 8, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 94 steps to reach 1.
LaTeX source of the formulas on this page
\[ 12221 = 11^{2} \times 101 \]12221 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 13566 |
| Euler totient Ļ(n) | 11000 |
| Square | 149352841 |
| Cube | 1825241069861 |
| Square root | 110.548632 (= 11ā101) |
| Digit sum / digital root | 8 / 8 |
| Collatz steps to 1 | 94 |
| Scientific notation | 1.2221 Ć |
12221 in other forms
| Form | Value |
|---|---|
| In words | twelve thousand two hundred and twenty-one |
| Binary (base 2) | 10111110111101 |
| Octal (base 8) | 27675 |
| Hexadecimal (base 16) | 2FBD |
| Base 3 | 121202122 |
| As time | 12221 seconds = 3 h 23 min 41 s |
Is 12221 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 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 8) | 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 | Yes (12221 Ć· 11 = 1111) | 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 12221 a prime number?
No. 12221 = Ć 101, so it is divisible by 11.
What are the factors of 12221?
1, 11, 101, 121, 1111, 12221.
What is 12221 in binary?
10111110111101 (hexadecimal 2FBD, octal 27675).
What is the square root of 12221?
About 110.5486, exactly 11ā101.
Is 12221 divisible by 3?
No. Its digits add up to 8, which is not a multiple of 3.
What is special about the number 12221?
12221 is a palindrome: it reads 12221 backwards too.