The number 11990
11990 is a composite number with 16 divisors. Its prime factorisation is 2 × 5 × 11 × 109. Divisors (16): 1, 2, 5, 10, 11, 22, 55, 109, 110, 218, 545, 1090, 1199, 2398, 5995, 11990.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
11990 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
11990 is composite. Its prime factorisation is
- 3
The divisors add up to 23760; without 11990 itself that is 11770, so 11990 is deficient (11770 is less than 11990). Euler's totient φ(11990) = 4320 numbers up to 11990 share no factor with it.
- 4
The digits of 11990 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 81 steps to reach 1.
LaTeX source of the formulas on this page
\[ 11990 = 2 \times 5 \times 11 \times 109 \]
11990 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 23760 |
| Euler totient φ(n) | 4320 |
| Square | 143760100 |
| Cube | 1723683599000 |
| Square root | 109.498858 |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 81 |
| Scientific notation | 1.199 × |
11990 in other forms
| Form | Value |
|---|---|
| In words | eleven thousand nine hundred and ninety |
| Binary (base 2) | 10111011010110 |
| Octal (base 8) | 27326 |
| Hexadecimal (base 16) | 2ED6 |
| Base 3 | 121110002 |
| As time | 11990 seconds = 3 h 19 min 50 s |
Is 11990 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (11990 ÷ 2 = 5995) | 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 | No (remainder 2) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (11990 ÷ 5 = 2398) | 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 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 | No (remainder 6) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 2) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | Yes (11990 ÷ 10 = 1199) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (11990 ÷ 11 = 1090) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 2) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 11990 a prime number?
No. 11990 = 2 × 5 × 11 × 109, so it is divisible by 2.
What are the factors of 11990?
1, 2, 5, 10, 11, 22, 55, 109, 110, 218, 545, 1090, 1199, 2398, 5995, 11990.
What is 11990 in binary?
10111011010110 (hexadecimal 2ED6, octal 27326).
What is the square root of 11990?
About 109.4989.
Is 11990 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 11990?
It is a composite number with 16 divisors.