The number 78442
78442 is a composite number with 16 divisors. Its prime factorisation is 2 × 7 × 13 × 431. Divisors (16): 1, 2, 7, 13, 14, 26, 91, 182, 431, 862, 3017, 5603, 6034, 11206, 39221, 78442.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
78442 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
78442 is composite. Its prime factorisation is
- 3
The divisors add up to 145152; without 78442 itself that is 66710, so 78442 is deficient (66710 is less than 78442). Euler's totient φ(78442) = 30960 numbers up to 78442 share no factor with it.
- 4
The digits of 78442 add up to 25, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 138 steps to reach 1.
LaTeX source of the formulas on this page
\[ 78442 = 2 \times 7 \times 13 \times 431 \]
78442 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 16 |
| Sum of divisors | 145152 |
| Euler totient φ(n) | 30960 |
| Square | 6153147364 |
| Cube | 482665185526888 |
| Square root | 280.074990 |
| Digit sum / digital root | 25 / 7 |
| Collatz steps to 1 | 138 |
| Scientific notation | 7.8442 × |
78442 in other forms
| Form | Value |
|---|---|
| In words | seventy-eight thousand four hundred and forty-two |
| Binary (base 2) | 10011001001101010 |
| Octal (base 8) | 231152 |
| Hexadecimal (base 16) | 1326A |
| Base 3 | 10222121021 |
| As time | 78442 seconds = 21 h 47 min 22 s |
Is 78442 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (78442 ÷ 2 = 39221) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 1) | 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 2) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (78442 ÷ 7 = 11206) | 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 | No (remainder 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 2) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 1) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 10) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 78442 a prime number?
No. 78442 = 2 × 7 × 13 × 431, so it is divisible by 2.
What are the factors of 78442?
1, 2, 7, 13, 14, 26, 91, 182, 431, 862, 3017, 5603, 6034, 11206, 39221, 78442.
What is 78442 in binary?
10011001001101010 (hexadecimal 1326A, octal 231152).
What is the square root of 78442?
About 280.0750.
Is 78442 divisible by 3?
No. Its digits add up to 25, which is not a multiple of 3.
What is special about the number 78442?
It is a composite number with 16 divisors.