The number 11820
11820 is a composite number with 24 divisors. Its prime factorisation is × 3 × 5 × 197. Divisors (24): 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60, 197, 394, 591, 788 … 11820.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 11820: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 12.
- 2
11820 is composite. Its prime factorisation is
- 3
The divisors add up to 33264; without 11820 itself that is 21444, so 11820 is abundant (21444 is more than 11820). Euler's totient φ(11820) = 3136 numbers up to 11820 share no factor with it.
- 4
The digits of 11820 add up to 12, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 143 steps to reach 1.
LaTeX source of the formulas on this page
\[ 11820 = 2^{2} \times 3 \times 5 \times 197 \]11820 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 33264 |
| Euler totient φ(n) | 3136 |
| Square | 139712400 |
| Cube | 1651400568000 |
| Square root | 108.719823 (= 2√2955) |
| Digit sum / digital root | 12 / 3 |
| Collatz steps to 1 | 143 |
| Scientific notation | 1.182 × |
11820 in other forms
| Form | Value |
|---|---|
| In words | eleven thousand eight hundred and twenty |
| Binary (base 2) | 10111000101100 |
| Octal (base 8) | 27054 |
| Hexadecimal (base 16) | 2E2C |
| Base 3 | 121012210 |
| As time | 11820 seconds = 3 h 17 min 0 s |
Is 11820 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (11820 ÷ 2 = 5910) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (11820 ÷ 3 = 3940) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (11820 ÷ 4 = 2955) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (11820 ÷ 5 = 2364) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (11820 ÷ 6 = 1970) | 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 4) | 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 | Yes (11820 ÷ 10 = 1182) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 6) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (11820 ÷ 12 = 985) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 11820 a prime number?
No. 11820 = × 3 × 5 × 197, so it is divisible by 2.
What are the factors of 11820?
1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30, 60, 197, 394, 591, 788, 985, 1182, 1970, 2364, 2955, 3940, 5910, 11820.
What is 11820 in binary?
10111000101100 (hexadecimal 2E2C, octal 27054).
What is the square root of 11820?
About 108.7198, exactly 2√2955.
Is 11820 divisible by 3?
Yes. Its digits add up to 12, a multiple of 3.
What is special about the number 11820?
11820 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 12.