The number 42315
42315 is a composite number with 32 divisors. Its prime factorisation is 3 × 5 × 7 × 13 × 31. Divisors (32): 1, 3, 5, 7, 13, 15, 21, 31, 35, 39, 65, 91, 93, 105, 155, 195 … 42315.
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How to work it out
- 1
What is special about 42315: a Harshad number: divisible by its digit sum 15.
- 2
42315 is composite. Its prime factorisation is
- 3
The divisors add up to 86016; without 42315 itself that is 43701, so 42315 is abundant (43701 is more than 42315). Euler's totient φ(42315) = 17280 numbers up to 42315 share no factor with it.
- 4
The digits of 42315 add up to 15, and repeating that until one digit is left gives the digital root 6. The Collatz sequence (halve if even, else 3n+1) takes 57 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42315 = 3 \times 5 \times 7 \times 13 \times 31 \]
42315 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 32 |
| Sum of divisors | 86016 |
| Euler totient φ(n) | 17280 |
| Square | 1790559225 |
| Cube | 75767513605875 |
| Square root | 205.706101 |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 57 |
| Scientific notation | 4.2315 × |
42315 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand three hundred and fifteen |
| Binary (base 2) | 1010010101001011 |
| Octal (base 8) | 122513 |
| Hexadecimal (base 16) | A54B |
| Base 3 | 2011001020 |
| As time | 42315 seconds = 11 h 45 min 15 s |
Is 42315 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | No (remainder 1) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | Yes (42315 ÷ 3 = 14105) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 3) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | Yes (42315 ÷ 5 = 8463) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 3) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | Yes (42315 ÷ 7 = 6045) | 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 3) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 6) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 9) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 3) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42315 a prime number?
No. 42315 = 3 × 5 × 7 × 13 × 31, so it is divisible by 3.
What are the factors of 42315?
1, 3, 5, 7, 13, 15, 21, 31, 35, 39, 65, 91, 93, 105, 155, 195, 217, 273, 403, 455, 465, 651, 1085, 1209, 1365, 2015, 2821, 3255, 6045, 8463, 14105, 42315.
What is 42315 in binary?
1010010101001011 (hexadecimal A54B, octal 122513).
What is the square root of 42315?
About 205.7061.
Is 42315 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 42315?
42315 is a Harshad number: divisible by its digit sum 15.