The number 42408
42408 is a composite number with 48 divisors. Its prime factorisation is × × 19 × 31. Divisors (48): 1, 2, 3, 4, 6, 8, 9, 12, 18, 19, 24, 31, 36, 38, 57, 62 … 42408.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42408: a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.
- 2
42408 is composite. Its prime factorisation is
- 3
The divisors add up to 124800; without 42408 itself that is 82392, so 42408 is abundant (82392 is more than 42408). Euler's totient φ(42408) = 12960 numbers up to 42408 share no factor with it.
- 4
The digits of 42408 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 31 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42408 = 2^{3} \times 3^{2} \times 19 \times 31 \]42408 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 48 |
| Sum of divisors | 124800 |
| Euler totient φ(n) | 12960 |
| Square | 1798438464 |
| Cube | 76268178381312 |
| Square root | 205.932028 (= 6√1178) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 31 |
| Scientific notation | 4.2408 × |
42408 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand four hundred and eight |
| Binary (base 2) | 1010010110101000 |
| Octal (base 8) | 122650 |
| Hexadecimal (base 16) | A5A8 |
| Base 3 | 2011011200 |
| As time | 42408 seconds = 11 h 46 min 48 s |
Is 42408 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (42408 ÷ 2 = 21204) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (42408 ÷ 3 = 14136) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (42408 ÷ 4 = 10602) | 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 (42408 ÷ 6 = 7068) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 (42408 ÷ 8 = 5301) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (42408 ÷ 9 = 4712) | 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 | Yes (42408 ÷ 12 = 3534) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42408 a prime number?
No. 42408 = × × 19 × 31, so it is divisible by 2.
What are the factors of 42408?
1, 2, 3, 4, 6, 8, 9, 12, 18, 19, 24, 31, 36, 38, 57, 62, 72, 76, 93, 114, 124, 152, 171, 186, 228, 248, 279, 342, 372, 456, 558, 589, 684, 744, 1116, 1178, 1368, 1767, 2232, 2356, 3534, 4712, 5301, 7068, 10602, 14136, 21204, 42408.
What is 42408 in binary?
1010010110101000 (hexadecimal A5A8, octal 122650).
What is the square root of 42408?
About 205.9320, exactly 6√1178.
Is 42408 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 42408?
42408 is a happy number: repeatedly adding the squares of its digits reaches 1; a Harshad number: divisible by its digit sum 18.