The number 42081
42081 is a composite number with 12 divisors. Its prime factorisation is 3 × × 83. Divisors (12): 1, 3, 13, 39, 83, 169, 249, 507, 1079, 3237, 14027, 42081.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
42081 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
42081 is composite. Its prime factorisation is
- 3
The divisors add up to 61488; without 42081 itself that is 19407, so 42081 is deficient (19407 is less than 42081). Euler's totient φ(42081) = 25584 numbers up to 42081 share no factor with it.
- 4
The digits of 42081 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 181 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42081 = 3 \times 13^{2} \times 83 \]42081 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 61488 |
| Euler totient φ(n) | 25584 |
| Square | 1770810561 |
| Cube | 74517479217441 |
| Square root | 205.136540 (= 13√249) |
| Digit sum / digital root | 15 / 6 |
| Collatz steps to 1 | 181 |
| Scientific notation | 4.2081 × |
42081 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand and eighty-one |
| Binary (base 2) | 1010010001100001 |
| Octal (base 8) | 122141 |
| Hexadecimal (base 16) | A461 |
| Base 3 | 2010201120 |
| As time | 42081 seconds = 11 h 41 min 21 s |
Is 42081 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 (42081 ÷ 3 = 14027) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | No (remainder 1) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 1) | 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 4) | 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 1) | 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 1) | 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 9) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42081 a prime number?
No. 42081 = 3 × × 83, so it is divisible by 3.
What are the factors of 42081?
1, 3, 13, 39, 83, 169, 249, 507, 1079, 3237, 14027, 42081.
What is 42081 in binary?
1010010001100001 (hexadecimal A461, octal 122141).
What is the square root of 42081?
About 205.1365, exactly 13√249.
Is 42081 divisible by 3?
Yes. Its digits add up to 15, a multiple of 3.
What is special about the number 42081?
It is a composite number with 12 divisors.