The number 11421
11421 is a composite number with 12 divisors. Its prime factorisation is × 47. Divisors (12): 1, 3, 9, 27, 47, 81, 141, 243, 423, 1269, 3807, 11421.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 11421: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 9.
- 2
11421 is composite. Its prime factorisation is
- 3
The divisors add up to 17472; without 11421 itself that is 6051, so 11421 is deficient (6051 is less than 11421). Euler's totient φ(11421) = 7452 numbers up to 11421 share no factor with it.
- 4
The digits of 11421 add up to 9, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 130 steps to reach 1.
LaTeX source of the formulas on this page
\[ 11421 = 3^{5} \times 47 \]11421 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 17472 |
| Euler totient φ(n) | 7452 |
| Square | 130439241 |
| Cube | 1489746571461 |
| Square root | 106.869079 (= 9√141) |
| Digit sum / digital root | 9 / 9 |
| Collatz steps to 1 | 130 |
| Scientific notation | 1.1421 × |
11421 in other forms
| Form | Value |
|---|---|
| In words | eleven thousand four hundred and twenty-one |
| Binary (base 2) | 10110010011101 |
| Octal (base 8) | 26235 |
| Hexadecimal (base 16) | 2C9D |
| Base 3 | 120200000 |
| As time | 11421 seconds = 3 h 10 min 21 s |
Is 11421 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 | Yes (11421 ÷ 3 = 3807) | 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 3) | 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (11421 ÷ 9 = 1269) | 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 3) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 11421 a prime number?
No. 11421 = × 47, so it is divisible by 3.
What are the factors of 11421?
1, 3, 9, 27, 47, 81, 141, 243, 423, 1269, 3807, 11421.
What is 11421 in binary?
10110010011101 (hexadecimal 2C9D, octal 26235).
What is the square root of 11421?
About 106.8691, exactly 9√141.
Is 11421 divisible by 3?
Yes. Its digits add up to 9, a multiple of 3.
What is special about the number 11421?
11421 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 9.