The number 42147
42147 is a composite number with 16 divisors. Its prime factorisation is × 7 × 223. Divisors (16): 1, 3, 7, 9, 21, 27, 63, 189, 223, 669, 1561, 2007, 4683, 6021, 14049, 42147.
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How to work it out
- 1
What is special about 42147: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
42147 is composite. Its prime factorisation is
- 3
The divisors add up to 71680; without 42147 itself that is 29533, so 42147 is deficient (29533 is less than 42147). Euler's totient φ(42147) = 23976 numbers up to 42147 share no factor with it.
- 4
The digits of 42147 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 80 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42147 = 3^{3} \times 7 \times 223 \]42147 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 71680 |
| Euler totient φ(n) | 23976 |
| Square | 1776369609 |
| Cube | 74868649910523 |
| Square root | 205.297345 (= 3√4683) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 80 |
| Scientific notation | 4.2147 × |
42147 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand one hundred and forty-seven |
| Binary (base 2) | 1010010010100011 |
| Octal (base 8) | 122243 |
| Hexadecimal (base 16) | A4A3 |
| Base 3 | 2010211000 |
| As time | 42147 seconds = 11 h 42 min 27 s |
Is 42147 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 (42147 ÷ 3 = 14049) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 2) | 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 | Yes (42147 ÷ 7 = 6021) | 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (42147 ÷ 9 = 4683) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 7) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42147 a prime number?
No. 42147 = × 7 × 223, so it is divisible by 3.
What are the factors of 42147?
1, 3, 7, 9, 21, 27, 63, 189, 223, 669, 1561, 2007, 4683, 6021, 14049, 42147.
What is 42147 in binary?
1010010010100011 (hexadecimal A4A3, octal 122243).
What is the square root of 42147?
About 205.2973, exactly 3√4683.
Is 42147 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 42147?
42147 is a happy number: repeatedly adding the squares of its digits reaches 1.