The number 21404
21404 is a composite number with 6 divisors. Its prime factorisation is × 5351. Divisors (6): 1, 2, 4, 5351, 10702, 21404.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
21404 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
21404 is composite. Its prime factorisation is
- 3
The divisors add up to 37464; without 21404 itself that is 16060, so 21404 is deficient (16060 is less than 21404). Euler's totient φ(21404) = 10700 numbers up to 21404 share no factor with it.
- 4
The digits of 21404 add up to 11, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 193 steps to reach 1.
LaTeX source of the formulas on this page
\[ 21404 = 2^{2} \times 5351 \]21404 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 6 |
| Sum of divisors | 37464 |
| Euler totient φ(n) | 10700 |
| Square | 458131216 |
| Cube | 9805840547264 |
| Square root | 146.301059 (= 2√5351) |
| Digit sum / digital root | 11 / 2 |
| Collatz steps to 1 | 193 |
| Scientific notation | 2.1404 × |
21404 in other forms
| Form | Value |
|---|---|
| In words | twenty-one thousand four hundred and four |
| Binary (base 2) | 101001110011100 |
| Octal (base 8) | 51634 |
| Hexadecimal (base 16) | 539C |
| Base 3 | 1002100202 |
| As time | 21404 seconds = 5 h 56 min 44 s |
Is 21404 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (21404 ÷ 2 = 10702) | 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 | Yes (21404 ÷ 4 = 5351) | 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 2) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | 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 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 8) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 21404 a prime number?
No. 21404 = × 5351, so it is divisible by 2.
What are the factors of 21404?
1, 2, 4, 5351, 10702, 21404.
What is 21404 in binary?
101001110011100 (hexadecimal 539C, octal 51634).
What is the square root of 21404?
About 146.3011, exactly 2√5351.
Is 21404 divisible by 3?
No. Its digits add up to 11, which is not a multiple of 3.
What is special about the number 21404?
It is a composite number with 6 divisors.