The number 18788
18788 is a composite number with 24 divisors. Its prime factorisation is × 7 × 11 × 61. Divisors (24): 1, 2, 4, 7, 11, 14, 22, 28, 44, 61, 77, 122, 154, 244, 308, 427 … 18788.
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How to work it out
- 1
18788 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
18788 is composite. Its prime factorisation is
- 3
The divisors add up to 41664; without 18788 itself that is 22876, so 18788 is abundant (22876 is more than 18788). Euler's totient φ(18788) = 7200 numbers up to 18788 share no factor with it.
- 4
The digits of 18788 add up to 32, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 110 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18788 = 2^{2} \times 7 \times 11 \times 61 \]18788 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 24 |
| Sum of divisors | 41664 |
| Euler totient φ(n) | 7200 |
| Square | 352988944 |
| Cube | 6631956279872 |
| Square root | 137.069326 (= 2√4697) |
| Digit sum / digital root | 32 / 5 |
| Collatz steps to 1 | 110 |
| Scientific notation | 1.8788 × |
18788 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand seven hundred and eighty-eight |
| Binary (base 2) | 100100101100100 |
| Octal (base 8) | 44544 |
| Hexadecimal (base 16) | 4964 |
| Base 3 | 221202212 |
| As time | 18788 seconds = 5 h 13 min 8 s |
Is 18788 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (18788 ÷ 2 = 9394) | 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 (18788 ÷ 4 = 4697) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 3) | 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 | Yes (18788 ÷ 7 = 2684) | 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 5) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 8) | A number is divisible by 10 if the last digit is 0. |
| 11 | Yes (18788 ÷ 11 = 1708) | 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 18788 a prime number?
No. 18788 = × 7 × 11 × 61, so it is divisible by 2.
What are the factors of 18788?
1, 2, 4, 7, 11, 14, 22, 28, 44, 61, 77, 122, 154, 244, 308, 427, 671, 854, 1342, 1708, 2684, 4697, 9394, 18788.
What is 18788 in binary?
100100101100100 (hexadecimal 4964, octal 44544).
What is the square root of 18788?
About 137.0693, exactly 2√4697.
Is 18788 divisible by 3?
No. Its digits add up to 32, which is not a multiple of 3.
What is special about the number 18788?
It is a composite number with 24 divisors.