The number 11840
11840 is a composite number with 28 divisors. Its prime factorisation is × 5 × 37. Divisors (28): 1, 2, 4, 5, 8, 10, 16, 20, 32, 37, 40, 64, 74, 80, 148, 160 … 11840.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 11840: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
11840 is composite. Its prime factorisation is
- 3
The divisors add up to 28956; without 11840 itself that is 17116, so 11840 is abundant (17116 is more than 11840). Euler's totient φ(11840) = 4608 numbers up to 11840 share no factor with it.
- 4
The digits of 11840 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 50 steps to reach 1.
LaTeX source of the formulas on this page
\[ 11840 = 2^{6} \times 5 \times 37 \]11840 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 28 |
| Sum of divisors | 28956 |
| Euler totient φ(n) | 4608 |
| Square | 140185600 |
| Cube | 1659797504000 |
| Square root | 108.811764 (= 8√185) |
| Digit sum / digital root | 14 / 5 |
| Collatz steps to 1 | 50 |
| Scientific notation | 1.184 × |
11840 in other forms
| Form | Value |
|---|---|
| In words | eleven thousand eight hundred and forty |
| Binary (base 2) | 10111001000000 |
| Octal (base 8) | 27100 |
| Hexadecimal (base 16) | 2E40 |
| Base 3 | 121020112 |
| As time | 11840 seconds = 3 h 17 min 20 s |
Is 11840 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (11840 ÷ 2 = 5920) | 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 (11840 ÷ 4 = 2960) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (11840 ÷ 5 = 2368) | 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 3) | 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 (11840 ÷ 8 = 1480) | 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 (11840 ÷ 10 = 1184) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 4) | 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 11840 a prime number?
No. 11840 = × 5 × 37, so it is divisible by 2.
What are the factors of 11840?
1, 2, 4, 5, 8, 10, 16, 20, 32, 37, 40, 64, 74, 80, 148, 160, 185, 296, 320, 370, 592, 740, 1184, 1480, 2368, 2960, 5920, 11840.
What is 11840 in binary?
10111001000000 (hexadecimal 2E40, octal 27100).
What is the square root of 11840?
About 108.8118, exactly 8√185.
Is 11840 divisible by 3?
No. Its digits add up to 14, which is not a multiple of 3.
What is special about the number 11840?
11840 is a happy number: repeatedly adding the squares of its digits reaches 1.