The number 21226
21226 is a composite number with 4 divisors. Its prime factorisation is 2 × 10613. Divisors (4): 1, 2, 10613, 21226.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 21226: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 2 × 10613, the product of two primes.
- 2
21226 is composite. Its prime factorisation is
- 3
The divisors add up to 31842; without 21226 itself that is 10616, so 21226 is deficient (10616 is less than 21226). Euler's totient φ(21226) = 10612 numbers up to 21226 share no factor with it.
- 4
The digits of 21226 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 30 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21226 = 2 \times 10613 \]
21226 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 31842 |
| Euler totient φ(n) | 10612 |
| Square | 450543076 |
| Cube | 9563227331176 |
| Square root | 145.691455 |
| Digit sum / digital root | 13 / 4 |
| Collatz steps to 1 | 30 |
| Scientific notation | 2.1226 × |
21226 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand two hundred and twenty-six |
| Binary (base 2) | 101001011101010 |
| Octal (base 8) | 51352 |
| Hexadecimal (base 16) | 52EA |
| Base 3 | 1002010011 |
| As time | 21226 seconds = 5 h 53 min 46 s |
Is 21226 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21226 ÷ 2 = 10613) | 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 | No (remainder 2) | 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 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 2) | 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 6) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 10) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21226 a prime number?
No. 21226 = 2 × 10613, so it is divisible by 2.
What are the factors of 21226?
1, 2, 10613, 21226.
What is 21226 in binary?
101001011101010 (hexadecimal 52EA, octal 51352).
What is the square root of 21226?
About 145.6915.
Is 21226 divisible by 3?
No. Its digits add up to 13, which is not a multiple of 3.
What is special about the number 21226?
21226 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 2 × 10613, the product of two primes.