The number 78408
78408 is a composite number with 60 divisors. Its prime factorisation is × × . Divisors (60): 1, 2, 3, 4, 6, 8, 9, 11, 12, 18, 22, 24, 27, 33, 36, 44 … 78408.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 78408: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 27.
- 2
78408 is composite. Its prime factorisation is
- 3
The divisors add up to 241395; without 78408 itself that is 162987, so 78408 is abundant (162987 is more than 78408). Euler's totient φ(78408) = 23760 numbers up to 78408 share no factor with it.
- 4
The digits of 78408 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 107 steps to reach 1.
LaTeX source of the formulas on this page
\[ 78408 = 2^{3} \times 3^{4} \times 11^{2} \]78408 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 60 |
| Sum of divisors | 241395 |
| Euler totient φ(n) | 23760 |
| Square | 6147814464 |
| Cube | 482037836493312 |
| Square root | 280.014285 (= 198√2) |
| Digit sum / digital root | 27 / 9 |
| Collatz steps to 1 | 107 |
| Scientific notation | 7.8408 × |
78408 in other forms
| Form | Value |
|---|---|
| In words | seventy-eight thousand four hundred and eight |
| Binary (base 2) | 10011001001001000 |
| Octal (base 8) | 231110 |
| Hexadecimal (base 16) | 13248 |
| Base 3 | 10222120000 |
| As time | 78408 seconds = 21 h 46 min 48 s |
Is 78408 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (78408 ÷ 2 = 39204) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (78408 ÷ 3 = 26136) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (78408 ÷ 4 = 19602) | 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 (78408 ÷ 6 = 13068) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 1) | 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 | Yes (78408 ÷ 8 = 9801) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (78408 ÷ 9 = 8712) | 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 | Yes (78408 ÷ 11 = 7128) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | Yes (78408 ÷ 12 = 6534) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 78408 a prime number?
No. 78408 = × × , so it is divisible by 2.
What are the factors of 78408?
1, 2, 3, 4, 6, 8, 9, 11, 12, 18, 22, 24, 27, 33, 36, 44, 54, 66, 72, 81, 88, 99, 108, 121, 132, 162, 198, 216, 242, 264, 297, 324, 363, 396, 484, 594, 648, 726, 792, 891, 968, 1089, 1188, 1452, 1782, 2178, 2376, 2904, 3267, 3564, 4356, 6534, 7128, 8712, 9801, 13068, 19602, 26136, 39204, 78408.
What is 78408 in binary?
10011001001001000 (hexadecimal 13248, octal 231110).
What is the square root of 78408?
About 280.0143, exactly 198√2.
Is 78408 divisible by 3?
Yes. Its digits add up to 27, a multiple of 3.
What is special about the number 78408?
78408 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 27.