The number 42731
42731 is a composite number with 8 divisors. Its prime factorisation is 13 × 19 × 173. Divisors (8): 1, 13, 19, 173, 247, 2249, 3287, 42731.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42731: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
42731 is composite. Its prime factorisation is
- 3
The divisors add up to 48720; without 42731 itself that is 5989, so 42731 is deficient (5989 is less than 42731). Euler's totient φ(42731) = 37152 numbers up to 42731 share no factor with it.
- 4
The digits of 42731 add up to 17, and repeating that until one digit is left gives the digital root 8. The Collatz sequence (halve if even, else 3n+1) takes 88 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42731 = 13 \times 19 \times 173 \]
42731 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 8 |
| Sum of divisors | 48720 |
| Euler totient φ(n) | 37152 |
| Square | 1825938361 |
| Cube | 78024172103891 |
| Square root | 206.714779 |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 88 |
| Scientific notation | 4.2731 × |
42731 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand seven hundred and thirty-one |
| Binary (base 2) | 1010011011101011 |
| Octal (base 8) | 123353 |
| Hexadecimal (base 16) | A6EB |
| Base 3 | 2011121122 |
| As time | 42731 seconds = 11 h 52 min 11 s |
Is 42731 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 | No (remainder 2) | 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 | No (remainder 1) | A number is divisible by 5 if the last digit is 0 or 5. |
| 6 | No (remainder 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 3) | 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 8) | 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 7) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 11) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 42731 a prime number?
No. 42731 = 13 × 19 × 173, so it is divisible by 13.
What are the factors of 42731?
1, 13, 19, 173, 247, 2249, 3287, 42731.
What is 42731 in binary?
1010011011101011 (hexadecimal A6EB, octal 123353).
What is the square root of 42731?
About 206.7148.
Is 42731 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 42731?
42731 is a happy number: repeatedly adding the squares of its digits reaches 1.