The number 42438
42438 is a composite number with 16 divisors. Its prime factorisation is 2 × 3 × 11 × 643. Divisors (16): 1, 2, 3, 6, 11, 22, 33, 66, 643, 1286, 1929, 3858, 7073, 14146, 21219, 42438.
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How to work it out
- 1
What is special about 42438: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
42438 is composite. Its prime factorisation is
- 3
The divisors add up to 92736; without 42438 itself that is 50298, so 42438 is abundant (50298 is more than 42438). Euler's totient φ(42438) = 12840 numbers up to 42438 share no factor with it.
- 4
The digits of 42438 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 31 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42438 = 2 \times 3 \times 11 \times 643 \]
42438 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 92736 |
| Euler totient φ(n) | 12840 |
| Square | 1800983844 |
| Cube | 76430152371672 |
| Square root | 206.004854 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 31 |
| Scientific notation | 4.2438 × |
42438 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand four hundred and thirty-eight |
| Binary (base 2) | 1010010111000110 |
| Octal (base 8) | 122706 |
| Hexadecimal (base 16) | A5C6 |
| Base 3 | 2011012210 |
| As time | 42438 seconds = 11 h 47 min 18 s |
Is 42438 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (42438 ÷ 2 = 21219) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (42438 ÷ 3 = 14146) | 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 3) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (42438 ÷ 6 = 7073) | 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 6) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 3) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 8) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (42438 ÷ 11 = 3858) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42438 a prime number?
No. 42438 = 2 × 3 × 11 × 643, so it is divisible by 2.
What are the factors of 42438?
1, 2, 3, 6, 11, 22, 33, 66, 643, 1286, 1929, 3858, 7073, 14146, 21219, 42438.
What is 42438 in binary?
1010010111000110 (hexadecimal A5C6, octal 122706).
What is the square root of 42438?
About 206.0049.
Is 42438 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 42438?
42438 is a happy number: repeatedly adding the squares of its digits reaches 1.