The number 43840
43840 is a composite number with 28 divisors. Its prime factorisation is × 5 × 137. Divisors (28): 1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 137, 160, 274, 320 … 43840.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
43840 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
43840 is composite. Its prime factorisation is
- 3
The divisors add up to 105156; without 43840 itself that is 61316, so 43840 is abundant (61316 is more than 43840). Euler's totient φ(43840) = 17408 numbers up to 43840 share no factor with it.
- 4
The digits of 43840 add up to 19, and repeating that until one digit is left gives the digital root 1. The Collatz sequence (halve if even, else 3n+1) takes 132 steps to reach 1.
LaTeX source of the formulas on this page
\[ 43840 = 2^{6} \times 5 \times 137 \]43840 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 28 |
| Sum of divisors | 105156 |
| Euler totient φ(n) | 17408 |
| Square | 1921945600 |
| Cube | 84258095104000 |
| Square root | 209.380037 (= 8√685) |
| Digit sum / digital root | 19 / 1 |
| Collatz steps to 1 | 132 |
| Scientific notation | 4.384 × |
43840 in other forms
| Form | Value |
|---|---|
| In words | forty-three thousand eight hundred and forty |
| Binary (base 2) | 1010101101000000 |
| Octal (base 8) | 125500 |
| Hexadecimal (base 16) | AB40 |
| Base 3 | 2020010201 |
| As time | 43840 seconds = 12 h 10 min 40 s |
Is 43840 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (43840 ÷ 2 = 21920) | 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 (43840 ÷ 4 = 10960) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (43840 ÷ 5 = 8768) | 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 | No (remainder 6) | 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 (43840 ÷ 8 = 5480) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 1) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (43840 ÷ 10 = 4384) | 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 43840 a prime number?
No. 43840 = × 5 × 137, so it is divisible by 2.
What are the factors of 43840?
1, 2, 4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 137, 160, 274, 320, 548, 685, 1096, 1370, 2192, 2740, 4384, 5480, 8768, 10960, 21920, 43840.
What is 43840 in binary?
1010101101000000 (hexadecimal AB40, octal 125500).
What is the square root of 43840?
About 209.3800, exactly 8√685.
Is 43840 divisible by 3?
No. Its digits add up to 19, which is not a multiple of 3.
What is special about the number 43840?
It is a composite number with 28 divisors.