The number 42813
42813 is a composite number with 12 divisors. Its prime factorisation is × 67 × 71. Divisors (12): 1, 3, 9, 67, 71, 201, 213, 603, 639, 4757, 14271, 42813.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 42813: a happy number: repeatedly adding the squares of its digits reaches 1.
- 2
42813 is composite. Its prime factorisation is
- 3
The divisors add up to 63648; without 42813 itself that is 20835, so 42813 is deficient (20835 is less than 42813). Euler's totient φ(42813) = 27720 numbers up to 42813 share no factor with it.
- 4
The digits of 42813 add up to 18, and repeating that until one digit is left gives the digital root 9. The Collatz sequence (halve if even, else 3n+1) takes 194 steps to reach 1.
LaTeX source of the formulas on this page
\[ 42813 = 3^{2} \times 67 \times 71 \]42813 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 12 |
| Sum of divisors | 63648 |
| Euler totient φ(n) | 27720 |
| Square | 1832952969 |
| Cube | 78474215461797 |
| Square root | 206.913025 (= 3√4757) |
| Digit sum / digital root | 18 / 9 |
| Collatz steps to 1 | 194 |
| Scientific notation | 4.2813 × |
42813 in other forms
| Form | Value |
|---|---|
| In words | forty-two thousand eight hundred and thirteen |
| Binary (base 2) | 1010011100111101 |
| Octal (base 8) | 123475 |
| Hexadecimal (base 16) | A73D |
| Base 3 | 2011201200 |
| As time | 42813 seconds = 11 h 53 min 33 s |
Is 42813 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 (42813 ÷ 3 = 14271) | 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 3) | 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 5) | A number is divisible by 8 if the last three digits make a multiple of 8. |
| 9 | Yes (42813 ÷ 9 = 4757) | A number is divisible by 9 if the digits add up to a multiple of 9. |
| 10 | No (remainder 3) | A number is divisible by 10 if the last digit is 0. |
| 11 | No (remainder 1) | 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 42813 a prime number?
No. 42813 = × 67 × 71, so it is divisible by 3.
What are the factors of 42813?
1, 3, 9, 67, 71, 201, 213, 603, 639, 4757, 14271, 42813.
What is 42813 in binary?
1010011100111101 (hexadecimal A73D, octal 123475).
What is the square root of 42813?
About 206.9130, exactly 3√4757.
Is 42813 divisible by 3?
Yes. Its digits add up to 18, a multiple of 3.
What is special about the number 42813?
42813 is a happy number: repeatedly adding the squares of its digits reaches 1.