The number 42078
42078 is a composite number with 8 divisors. Its prime factorisation is 2 × 3 × 7013. Divisors (8): 1, 2, 3, 6, 7013, 14026, 21039, 42078.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42078: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
42078 is composite. Its prime factorisation is
- 3
The divisors add up to 84168; without 42078 itself that is 42090, so 42078 is abundant (42090 is more than 42078). Euler's totient φ(42078) = 14024 numbers up to 42078 share no factor with it.
- 4
The digits of 42078 add up to 21, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 225 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42078 = 2 \times 3 \times 7013 \]
42078 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 84168 |
| Euler totient φ(n) | 14024 |
| Square | 1770558084 |
| Cube | 74501543058552 |
| Square root | 205.129228 |
| Digit sum / digital root | 21 / 3 |
| Collatz steps to 1 | 225 |
| Scientific notation | 4.2078 × |
42078 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand and seventy-eight |
| Binary (base 2) | 1010010001011110 |
| Octal (base 8) | 122136 |
| Hexadecimal (base 16) | A45E |
| Base 3 | 2010201110 |
| As time | 42078 seconds = 11 h 41 min 18 s |
Is 42078 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (42078 ÷ 2 = 21039) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (42078 ÷ 3 = 14026) | 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 (42078 ÷ 6 = 7013) | 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 | 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 3) | 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 42078 a prime number?
No. 42078 = 2 × 3 × 7013, so it is divisible by 2.
What are the factors of 42078?
1, 2, 3, 6, 7013, 14026, 21039, 42078.
What is 42078 in binary?
1010010001011110 (hexadecimal A45E, octal 122136).
What is the square root of 42078?
About 205.1292.
Is 42078 divisible by 3?
Yes. Its digits add up to 21, a multiple of 3.
What is special about the number 42078?
42078 is a happy number: repeatedly adding the squares of its digits reaches 1.