The number 42800
42800 is a composite number with 30 divisors. Its prime factorisation is × × 107. Divisors (30): 1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 107, 200, 214 … 42800.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
42800 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
42800 is composite. Its prime factorisation is
- 3
The divisors add up to 103788; without 42800 itself that is 60988, so 42800 is abundant (60988 is more than 42800). Euler's totient φ(42800) = 16960 numbers up to 42800 share no factor with it.
- 4
The digits of 42800 add up to 14, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 49 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42800 = 2^{4} \times 5^{2} \times 107 \]42800 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 30 |
| Sum of divisors | 103788 |
| Euler totient φ(n) | 16960 |
| Square | 1831840000 |
| Cube | 78402752000000 |
| Square root | 206.881609 (= 20√107) |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 49 |
| Scientific notation | 4.28 × |
42800 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand eight hundred |
| Binary (base 2) | 1010011100110000 |
| Octal (base 8) | 123460 |
| Hexadecimal (base 16) | A730 |
| Base 3 | 2011201012 |
| As time | 42800 seconds = 11 h 53 min 20 s |
Is 42800 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (42800 ÷ 2 = 21400) | 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 (42800 ÷ 4 = 10700) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (42800 ÷ 5 = 8560) | 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 2) | 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 (42800 ÷ 8 = 5350) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (42800 ÷ 10 = 4280) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 10) | 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 42800 a prime number?
No. 42800 = × × 107, so it is divisible by 2.
What are the factors of 42800?
1, 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, 107, 200, 214, 400, 428, 535, 856, 1070, 1712, 2140, 2675, 4280, 5350, 8560, 10700, 21400, 42800.
What is 42800 in binary?
1010011100110000 (hexadecimal A730, octal 123460).
What is the square root of 42800?
About 206.8816, exactly 20√107.
Is 42800 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 42800?
It is a composite number with 30 divisors.