The number 78138
78138 is a composite number with 16 divisors. Its prime factorisation is 2 × × 1447. Divisors (16): 1, 2, 3, 6, 9, 18, 27, 54, 1447, 2894, 4341, 8682, 13023, 26046, 39069, 78138.
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How to work it out
- 1
What is special about 78138: a Harshad number: divisible by its digit sum 27.
- 2
78138 is composite. Its prime factorisation is
- 3
The divisors add up to 173760; without 78138 itself that is 95622, so 78138 is abundant (95622 is more than 78138). Euler's totient φ(78138) = 26028 numbers up to 78138 share no factor with it.
- 4
The digits of 78138 add up to 27, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 76 steps to reach 1.
LaTeX source of the formulas on this page
\[ 78138 = 2 \times 3^{3} \times 1447 \]78138 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 173760 |
| Euler totient φ(n) | 26028 |
| Square | 6105547044 |
| Cube | 477075234924072 |
| Square root | 279.531751 (= 3√8682) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 76 |
| Scientific notation | 7.8138 × |
78138 in other forms
| Form | Value |
|---|---|
| In words | seventy-eight thousand one hundred and thirty-eight |
| Binary (base 2) | 10011000100111010 |
| Octal (base 8) | 230472 |
| Hexadecimal (base 16) | 1313A |
| Base 3 | 10222012000 |
| As time | 78138 seconds = 21 h 42 min 18 s |
Is 78138 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (78138 ÷ 2 = 39069) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (78138 ÷ 3 = 26046) | 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 (78138 ÷ 6 = 13023) | 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 2) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (78138 ÷ 9 = 8682) | 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 5) | 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 78138 a prime number?
No. 78138 = 2 × × 1447, so it is divisible by 2.
What are the factors of 78138?
1, 2, 3, 6, 9, 18, 27, 54, 1447, 2894, 4341, 8682, 13023, 26046, 39069, 78138.
What is 78138 in binary?
10011000100111010 (hexadecimal 1313A, octal 230472).
What is the square root of 78138?
About 279.5318, exactly 3√8682.
Is 78138 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 78138?
78138 is a Harshad number: divisible by its digit sum 27.