The number 42784
42784 is a composite number with 24 divisors. Its prime factorisation is × 7 × 191. Divisors (24): 1, 2, 4, 7, 8, 14, 16, 28, 32, 56, 112, 191, 224, 382, 764, 1337 … 42784.
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How to work it out
- 1
42784 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
42784 is composite. Its prime factorisation is
- 3
The divisors add up to 96768; without 42784 itself that is 53984, so 42784 is abundant (53984 is more than 42784). Euler's totient φ(42784) = 18240 numbers up to 42784 share no factor with it.
- 4
The digits of 42784 add up to 25, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 49 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42784 = 2^{5} \times 7 \times 191 \]42784 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 96768 |
| Euler totient φ(n) | 18240 |
| Square | 1830470656 |
| Cube | 78314856546304 |
| Square root | 206.842936 (= 4√2674) |
| Digit sum / digital root | 25 / 7 |
| Collatz steps to 1 | 49 |
| Scientific notation | 4.2784 × |
42784 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand seven hundred and eighty-four |
| Binary (base 2) | 1010011100100000 |
| Octal (base 8) | 123440 |
| Hexadecimal (base 16) | A720 |
| Base 3 | 2011200121 |
| As time | 42784 seconds = 11 h 53 min 4 s |
Is 42784 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (42784 ÷ 2 = 21392) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 1) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (42784 ÷ 4 = 10696) | 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 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (42784 ÷ 7 = 6112) | 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 | Yes (42784 ÷ 8 = 5348) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | 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 5) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42784 a prime number?
No. 42784 = × 7 × 191, so it is divisible by 2.
What are the factors of 42784?
1, 2, 4, 7, 8, 14, 16, 28, 32, 56, 112, 191, 224, 382, 764, 1337, 1528, 2674, 3056, 5348, 6112, 10696, 21392, 42784.
What is 42784 in binary?
1010011100100000 (hexadecimal A720, octal 123440).
What is the square root of 42784?
About 206.8429, exactly 4√2674.
Is 42784 divisible by 3?
No. Its digits add up to 25, which is not a multiple of 3.
What is special about the number 42784?
It is a composite number with 24 divisors.