The number 42978
42978 is a composite number with 32 divisors. Its prime factorisation is 2 × 3 × 13 × 19 × 29. Divisors (32): 1, 2, 3, 6, 13, 19, 26, 29, 38, 39, 57, 58, 78, 87, 114, 174 … 42978.
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How to work it out
- 1
42978 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
42978 is composite. Its prime factorisation is
- 3
The divisors add up to 100800; without 42978 itself that is 57822, so 42978 is abundant (57822 is more than 42978). Euler's totient φ(42978) = 12096 numbers up to 42978 share no factor with it.
- 4
The digits of 42978 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 101 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42978 = 2 \times 3 \times 13 \times 19 \times 29 \]
42978 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 100800 |
| Euler totient φ(n) | 12096 |
| Square | 1847108484 |
| Cube | 79385028425352 |
| Square root | 207.311360 |
| Digit sum / digital root | 30 / 3 |
| Collatz steps to 1 | 101 |
| Scientific notation | 4.2978 × |
42978 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand nine hundred and seventy-eight |
| Binary (base 2) | 1010011111100010 |
| Octal (base 8) | 123742 |
| Hexadecimal (base 16) | A7E2 |
| Base 3 | 2011221210 |
| As time | 42978 seconds = 11 h 56 min 18 s |
Is 42978 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (42978 ÷ 2 = 21489) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (42978 ÷ 3 = 14326) | 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 (42978 ÷ 6 = 7163) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 5) | 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 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 1) | 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 42978 a prime number?
No. 42978 = 2 × 3 × 13 × 19 × 29, so it is divisible by 2.
What are the factors of 42978?
1, 2, 3, 6, 13, 19, 26, 29, 38, 39, 57, 58, 78, 87, 114, 174, 247, 377, 494, 551, 741, 754, 1102, 1131, 1482, 1653, 2262, 3306, 7163, 14326, 21489, 42978.
What is 42978 in binary?
1010011111100010 (hexadecimal A7E2, octal 123742).
What is the square root of 42978?
About 207.3114.
Is 42978 divisible by 3?
Yes. Its digits add up to 30, a multiple of 3.
What is special about the number 42978?
It is a composite number with 32 divisors.