The number 71381
71381 is a composite number with 4 divisors. Its prime factorisation is 41 × 1741. Divisors (4): 1, 41, 1741, 71381.
Pick any whole number from 1 to 100,000.
How to work it out
- 1
What is special about 71381: a semiprime: 41 × 1741, the product of two primes.
- 2
71381 is composite. Its prime factorisation is
- 3
The divisors add up to 73164; without 71381 itself that is 1783, so 71381 is deficient (1783 is less than 71381). Euler's totient φ(71381) = 69600 numbers up to 71381 share no factor with it.
- 4
The digits of 71381 add up to 20, and repeating that until one digit is left gives the digital root 2. The Collatz sequence (halve if even, else 3n+1) takes 99 steps to reach 1.
LaTeX source of the formulas on this page
\[ 71381 = 41 \times 1741 \]
71381 at a glance
| Property | Value |
|---|---|
| Type | composite |
| Number of divisors | 4 |
| Sum of divisors | 73164 |
| Euler totient φ(n) | 69600 |
| Square | 5095247161 |
| Cube | 363703837599341 |
| Square root | 267.172229 |
| Digit sum / digital root | 20 / 2 |
| Collatz steps to 1 | 99 |
| Scientific notation | 7.1381 × |
71381 in other forms
| Form | Value |
|---|---|
| In words | seventy-one thousand three hundred and eighty-one |
| Binary (base 2) | 10001011011010101 |
| Octal (base 8) | 213325 |
| Hexadecimal (base 16) | 116D5 |
| Base 3 | 10121220202 |
| As time | 71381 seconds = 19 h 49 min 41 s |
Is 71381 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 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 5) | A number is divisible by 6 if it is divisible by both 2 and 3. |
| 7 | No (remainder 2) | 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 | No (remainder 2) | 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 2) | A number is divisible by 11 if the alternating sum of the digits is a multiple of 11. |
| 12 | No (remainder 5) | A number is divisible by 12 if it is divisible by both 3 and 4. |
Questions
Is 71381 a prime number?
No. 71381 = 41 × 1741, so it is divisible by 41.
What are the factors of 71381?
1, 41, 1741, 71381.
What is 71381 in binary?
10001011011010101 (hexadecimal 116D5, octal 213325).
What is the square root of 71381?
About 267.1722.
Is 71381 divisible by 3?
No. Its digits add up to 20, which is not a multiple of 3.
What is special about the number 71381?
71381 is a semiprime: 41 × 1741, the product of two primes.