The number 78438
78438 is a composite number with 16 divisors. Its prime factorisation is 2 × 3 × 17 × 769. Divisors (16): 1, 2, 3, 6, 17, 34, 51, 102, 769, 1538, 2307, 4614, 13073, 26146, 39219, 78438.
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How to work it out
- 1
78438 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
78438 is composite. Its prime factorisation is
- 3
The divisors add up to 166320; without 78438 itself that is 87882, so 78438 is abundant (87882 is more than 78438). Euler's totient φ(78438) = 24576 numbers up to 78438 share no factor with it.
- 4
The digits of 78438 add up to 30, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 169 steps to reach 1.
LaTeX source of the formulas on this page
\[ 78438 = 2 \times 3 \times 17 \times 769 \]
78438 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 166320 |
| Euler totient φ(n) | 24576 |
| Square | 6152519844 |
| Cube | 482591351523672 |
| Square root | 280.067849 |
| Digit sum / digital root | 30 / 3 |
| Collatz steps to 1 | 169 |
| Scientific notation | 7.8438 × |
78438 in other forms
| Form | Value |
|---|---|
| In words | seventy-eight thousand four hundred and thirty-eight |
| Binary (base 2) | 10011001001100110 |
| Octal (base 8) | 231146 |
| Hexadecimal (base 16) | 13266 |
| Base 3 | 10222121010 |
| As time | 78438 seconds = 21 h 47 min 18 s |
Is 78438 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (78438 ÷ 2 = 39219) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (78438 ÷ 3 = 26146) | 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 (78438 ÷ 6 = 13073) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | 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 3) | 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 8) | 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 78438 a prime number?
No. 78438 = 2 × 3 × 17 × 769, so it is divisible by 2.
What are the factors of 78438?
1, 2, 3, 6, 17, 34, 51, 102, 769, 1538, 2307, 4614, 13073, 26146, 39219, 78438.
What is 78438 in binary?
10011001001100110 (hexadecimal 13266, octal 231146).
What is the square root of 78438?
About 280.0678.
Is 78438 divisible by 3?
Yes. Its digits add up to 30, a multiple of 3.
What is special about the number 78438?
It is a composite number with 16 divisors.