243is an odd number,as it is not divisible by 2
The factors for 243 are all the numbers between -243 and 243 , which divide 243 without leaving any remainder. Since 243 divided by -243 is an integer, -243 is a factor of 243 .
Since 243 divided by -243 is a whole number, -243 is a factor of 243
Since 243 divided by -81 is a whole number, -81 is a factor of 243
Since 243 divided by -27 is a whole number, -27 is a factor of 243
Since 243 divided by -9 is a whole number, -9 is a factor of 243
Since 243 divided by -3 is a whole number, -3 is a factor of 243
Since 243 divided by -1 is a whole number, -1 is a factor of 243
Multiples of 243 are all integers divisible by 243 , i.e. the remainder of the full division by 243 is zero. There are infinite multiples of 243. The smallest multiples of 243 are:
It is possible to determine using mathematical techniques whether an integer is prime or not.
for 243, the answer is: No, 243 is not a prime number.
To know the primality of an integer, we can use several algorithms. The most naive is to try all divisors below the number you want to know if it is prime (in our case 243). We can already eliminate even numbers bigger than 2 (then 4 , 6 , 8 ...). Besides, we can stop at the square root of the number in question (here 15.588 ). Historically, the Eratosthenes screen (which dates back to Antiquity) uses this technique relatively effectively.
More modern techniques include the Atkin screen, probabilistic tests, or the cyclotomic test.
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Next prime number: 251