The number 18428
18428 is a composite number with 12 divisors. Its prime factorisation is × 17 × 271. Divisors (12): 1, 2, 4, 17, 34, 68, 271, 542, 1084, 4607, 9214, 18428.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
18428 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
18428 is composite. Its prime factorisation is
- 3
The divisors add up to 34272; without 18428 itself that is 15844, so 18428 is deficient (15844 is less than 18428). Euler's totient φ(18428) = 8640 numbers up to 18428 share no factor with it.
- 4
The digits of 18428 add up to 23, and repeating that until one digit is left gives the digital root 5. The Collatz sequence (halve if even, else 3n+1) takes 154 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18428 = 2^{2} \times 17 \times 271 \]18428 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 34272 |
| Euler totient φ(n) | 8640 |
| Square | 339591184 |
| Cube | 6257986338752 |
| Square root | 135.749770 (= 2√4607) |
| Digit sum / digital root | 23 / 5 |
| Collatz steps to 1 | 154 |
| Scientific notation | 1.8428 × |
18428 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand four hundred and twenty-eight |
| Binary (base 2) | 100011111111100 |
| Octal (base 8) | 43774 |
| Hexadecimal (base 16) | 47FC |
| Base 3 | 221021112 |
| As time | 18428 seconds = 5 h 7 min 8 s |
Is 18428 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (18428 ÷ 2 = 9214) | 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 (18428 ÷ 4 = 4607) | 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 | 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 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 | No (remainder 3) | 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 18428 a prime number?
No. 18428 = × 17 × 271, so it is divisible by 2.
What are the factors of 18428?
1, 2, 4, 17, 34, 68, 271, 542, 1084, 4607, 9214, 18428.
What is 18428 in binary?
100011111111100 (hexadecimal 47FC, octal 43774).
What is the square root of 18428?
About 135.7498, exactly 2√4607.
Is 18428 divisible by 3?
No. Its digits add up to 23, which is not a multiple of 3.
What is special about the number 18428?
It is a composite number with 12 divisors.