The number 71243
71243 is a composite number with 4 divisors. Its prime factorisation is 191 × 373. Divisors (4): 1, 191, 373, 71243.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 71243: a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 191 × 373, the product of two primes.
- 2
71243 is composite. Its prime factorisation is
- 3
The divisors add up to 71808; without 71243 itself that is 565, so 71243 is deficient (565 is less than 71243). Euler's totient φ(71243) = 70680 numbers up to 71243 share no factor with it.
- 4
The digits of 71243 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 99 steps to reach 1.
LaTeX source of the formulas on this page
\[ 71243 = 191 \times 373 \]
71243 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 71808 |
| Euler totient φ(n) | 70680 |
| Square | 5075565049 |
| Cube | 361598480785907 |
| Square root | 266.913844 |
| Digit sum / digital root | 17 / 8 |
| Collatz steps to 1 | 99 |
| Scientific notation | 7.1243 × |
71243 in other forms
| Form | Value |
|---|---|
| In words | seventy-one thousand two hundred and forty-three |
| Binary (base 2) | 10001011001001011 |
| Octal (base 8) | 213113 |
| Hexadecimal (base 16) | 1164B |
| Base 3 | 10121201122 |
| As time | 71243 seconds = 19 h 47 min 23 s |
Is 71243 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 3) | 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 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 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 3) | 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 71243 a prime number?
No. 71243 = 191 × 373, so it is divisible by 191.
What are the factors of 71243?
1, 191, 373, 71243.
What is 71243 in binary?
10001011001001011 (hexadecimal 1164B, octal 213113).
What is the square root of 71243?
About 266.9138.
Is 71243 divisible by 3?
No. Its digits add up to 17, which is not a multiple of 3.
What is special about the number 71243?
71243 is a happy number: repeatedly adding the squares of its digits reaches 1; a semiprime: 191 × 373, the product of two primes.