The number 42172
42172 is a composite number with 12 divisors. Its prime factorisation is × 13 × 811. Divisors (12): 1, 2, 4, 13, 26, 52, 811, 1622, 3244, 10543, 21086, 42172.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
42172 has no famous special property in the usual lists (prime, square, cube, triangular, Fibonacci, palindrome, perfect), but it is still a composite number.
- 2
42172 is composite. Its prime factorisation is
- 3
The divisors add up to 79576; without 42172 itself that is 37404, so 42172 is deficient (37404 is less than 42172). Euler's totient φ(42172) = 19440 numbers up to 42172 share no factor with it.
- 4
The digits of 42172 add up to 16, and repeating that until one digit is left gives the digital root 7. The Collatz sequence (halve if even, else 3n+1) takes 181 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42172 = 2^{2} \times 13 \times 811 \]42172 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 79576 |
| Euler totient φ(n) | 19440 |
| Square | 1778477584 |
| Cube | 75001956672448 |
| Square root | 205.358224 (= 2√10543) |
| Digit sum / digital root | 16 / 7 |
| Collatz steps to 1 | 181 |
| Scientific notation | 4.2172 × |
42172 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand one hundred and seventy-two |
| Binary (base 2) | 1010010010111100 |
| Octal (base 8) | 122274 |
| Hexadecimal (base 16) | A4BC |
| Base 3 | 2010211221 |
| As time | 42172 seconds = 11 h 42 min 52 s |
Is 42172 divisible by 2 to 12?
| Divisor | Answer | Rule |
|---|---|---|
| 2 | Yes (42172 ÷ 2 = 21086) | A number is divisible by 2 if the last digit is even (0, 2, 4, 6, 8). |
| 3 | No (remainder 1) | A number is divisible by 3 if the digits add up to a multiple of 3. |
| 4 | Yes (42172 ÷ 4 = 10543) | A number is divisible by 4 if the last two digits make a multiple of 4. |
| 5 | No (remainder 2) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 4) | 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 4) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | No (remainder 7) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 2) | 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 4) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42172 a prime number?
No. 42172 = × 13 × 811, so it is divisible by 2.
What are the factors of 42172?
1, 2, 4, 13, 26, 52, 811, 1622, 3244, 10543, 21086, 42172.
What is 42172 in binary?
1010010010111100 (hexadecimal A4BC, octal 122274).
What is the square root of 42172?
About 205.3582, exactly 2√10543.
Is 42172 divisible by 3?
No. Its digits add up to 16, which is not a multiple of 3.
What is special about the number 42172?
It is a composite number with 12 divisors.