The number 42015
42015 is a composite number with 8 divisors. Its prime factorisation is 3 × 5 × 2801. Divisors (8): 1, 3, 5, 15, 2801, 8403, 14005, 42015.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
42015 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
42015 is composite. Its prime factorisation is
- 3
The divisors add up to 67248; without 42015 itself that is 25233, so 42015 is deficient (25233 is less than 42015). Euler's totient φ(42015) = 22400 numbers up to 42015 share no factor with it.
- 4
The digits of 42015 add up to 12, and repeating that until one digit is left gives the digital root 3. The Collatz sequence (halve if even, else 3n+1) takes 132 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42015 = 3 \times 5 \times 2801 \]
42015 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 67248 |
| Euler totient φ(n) | 22400 |
| Square | 1765260225 |
| Cube | 74167408353375 |
| Square root | 204.975608 |
| Digit sum / digital root | 12 / 3 |
| Collatz steps to 1 | 132 |
| Scientific notation | 4.2015 × |
42015 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand and fifteen |
| Binary (base 2) | 1010010000011111 |
| Octal (base 8) | 122037 |
| Hexadecimal (base 16) | A41F |
| Base 3 | 2010122010 |
| As time | 42015 seconds = 11 h 40 min 15 s |
Is 42015 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 (42015 ÷ 3 = 14005) | 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 (42015 ÷ 5 = 8403) | 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 | 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 7) | 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 5) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 6) | 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 42015 a prime number?
No. 42015 = 3 × 5 × 2801, so it is divisible by 3.
What are the factors of 42015?
1, 3, 5, 15, 2801, 8403, 14005, 42015.
What is 42015 in binary?
1010010000011111 (hexadecimal A41F, octal 122037).
What is the square root of 42015?
About 204.9756.
Is 42015 divisible by 3?
Yes. Its digits add up to 12, a multiple of 3.
What is special about the number 42015?
It is a composite number with 8 divisors.