The number 47421
47421 is a composite number with 12 divisors. Its prime factorisation is × 11 × 479. Divisors (12): 1, 3, 9, 11, 33, 99, 479, 1437, 4311, 5269, 15807, 47421.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 47421: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
47421 is composite. Its prime factorisation is
- 3
The divisors add up to 74880; without 47421 itself that is 27459, so 47421 is deficient (27459 is less than 47421). Euler's totient φ(47421) = 28680 numbers up to 47421 share no factor with it.
- 4
The digits of 47421 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 75 steps to reach 1.
LaTeX source of the formulas on this page
\[ 47421 = 3^{2} \times 11 \times 479 \]47421 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 74880 |
| Euler totient φ(n) | 28680 |
| Square | 2248751241 |
| Cube | 106638032599461 |
| Square root | 217.763633 (= 3√5269) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 75 |
| Scientific notation | 4.7421 × |
47421 in other forms
| Form | Value |
|---|---|
| In words | forty-seven thousand four hundred and twenty-one |
| Binary (base 2) | 1011100100111101 |
| Octal (base 8) | 134475 |
| Hexadecimal (base 16) | B93D |
| Base 3 | 2102001100 |
| As time | 47421 seconds = 13 h 10 min 21 s |
Is 47421 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 (47421 ÷ 3 = 15807) | 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 3) | 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 (47421 ÷ 9 = 5269) | 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 (47421 ÷ 11 = 4311) | 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 47421 a prime number?
No. 47421 = × 11 × 479, so it is divisible by 3.
What are the factors of 47421?
1, 3, 9, 11, 33, 99, 479, 1437, 4311, 5269, 15807, 47421.
What is 47421 in binary?
1011100100111101 (hexadecimal B93D, octal 134475).
What is the square root of 47421?
About 217.7636, exactly 3√5269.
Is 47421 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 47421?
47421 is a happy number: repeatedly adding the squares of its digits reaches 1.