The number 18438
18438 is a composite number with 16 divisors. Its prime factorisation is 2 × 3 × 7 × 439. Divisors (16): 1, 2, 3, 6, 7, 14, 21, 42, 439, 878, 1317, 2634, 3073, 6146, 9219, 18438.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
18438 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
18438 is composite. Its prime factorisation is
- 3
The divisors add up to 42240; without 18438 itself that is 23802, so 18438 is abundant (23802 is more than 18438). Euler's totient φ(18438) = 5256 numbers up to 18438 share no factor with it.
- 4
The digits of 18438 add up to 24, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 48 steps to reach 1.
LaTeX source of the formulas on this page
\[ 18438 = 2 \times 3 \times 7 \times 439 \]
18438 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 42240 |
| Euler totient φ(n) | 5256 |
| Square | 339959844 |
| Cube | 6268179603672 |
| Square root | 135.786597 |
| Digit sum / digital root | 24 / 6 |
| Collatz steps to 1 | 48 |
| Scientific notation | 1.8438 × |
18438 in other forms
| Form | Value |
|---|---|
| In words | eighteen thousand four hundred and thirty-eight |
| Binary (base 2) | 100100000000110 |
| Octal (base 8) | 44006 |
| Hexadecimal (base 16) | 4806 |
| Base 3 | 221021220 |
| As time | 18438 seconds = 5 h 7 min 18 s |
Is 18438 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (18438 ÷ 2 = 9219) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (18438 ÷ 3 = 6146) | 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 | No (remainder 3) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | Yes (18438 ÷ 6 = 3073) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (18438 ÷ 7 = 2634) | 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 6) | 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 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 6) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 18438 a prime number?
No. 18438 = 2 × 3 × 7 × 439, so it is divisible by 2.
What are the factors of 18438?
1, 2, 3, 6, 7, 14, 21, 42, 439, 878, 1317, 2634, 3073, 6146, 9219, 18438.
What is 18438 in binary?
100100000000110 (hexadecimal 4806, octal 44006).
What is the square root of 18438?
About 135.7866.
Is 18438 divisible by 3?
Yes. Its digits add up to 24, a multiple of 3.
What is special about the number 18438?
It is a composite number with 16 divisors.