The number 438
438 is a composite number with 8 divisors. Its prime factorisation is 2 × 3 × 73. Divisors (8): 1, 2, 3, 6, 73, 146, 219, 438.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
438 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
438 is composite. Its prime factorisation is
- 3
The divisors add up to 888; without 438 itself that is 450, so 438 is abundant (450 is more than 438). Euler's totient φ(438) = 144 numbers up to 438 share no factor with it.
- 4
The digits of 438 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 53 steps to reach 1.
LaTeX source of the formulas on this page
\[ 438 = 2 \times 3 \times 73 \]
438 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 888 |
| Euler totient φ(n) | 144 |
| Square | 191844 |
| Cube | 84027672 |
| Square root | 20.928450 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 53 |
| Scientific notation | 4.38 × |
438 in other forms
| Form | Value |
|---|---|
| In words | four hundred and thirty-eight |
| Roman numerals | CDXXXVIII |
| Binary (base 2) | 110110110 |
| Octal (base 8) | 666 |
| Hexadecimal (base 16) | 1B6 |
| Base 3 | 121020 |
| As time | 438 seconds = 7 min 18 s |
Is 438 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (438 ÷ 2 = 219) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (438 ÷ 3 = 146) | 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 (438 ÷ 6 = 73) | 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 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 9) | 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 438 a prime number?
No. 438 = 2 × 3 × 73, so it is divisible by 2.
What are the factors of 438?
1, 2, 3, 6, 73, 146, 219, 438.
What is 438 in binary?
110110110 (hexadecimal 1B6, octal 666).
What is the square root of 438?
About 20.9284.
What is 438 in Roman numerals?
CDXXXVIII.
Is 438 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 438?
It is a composite number with 8 divisors.