In addition we can say of the number 30 that it is even
30 is an even number, as it is divisible by 2 : 30/2 = 15
The factors for 30 are all the numbers between -30 and 30 , which divide 30 without leaving any remainder. Since 30 divided by -30 is an integer, -30 is a factor of 30 .
Since 30 divided by -30 is a whole number, -30 is a factor of 30
Since 30 divided by -15 is a whole number, -15 is a factor of 30
Since 30 divided by -10 is a whole number, -10 is a factor of 30
Since 30 divided by -6 is a whole number, -6 is a factor of 30
Since 30 divided by -5 is a whole number, -5 is a factor of 30
Since 30 divided by -3 is a whole number, -3 is a factor of 30
Since 30 divided by -2 is a whole number, -2 is a factor of 30
Since 30 divided by -1 is a whole number, -1 is a factor of 30
Multiples of 30 are all integers divisible by 30 , i.e. the remainder of the full division by 30 is zero. There are infinite multiples of 30. The smallest multiples of 30 are:
It is possible to determine using mathematical techniques whether an integer is prime or not.
for 30, the answer is: No, 30 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 30). 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 5.477 ). 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.
Previous prime number: 29
Next prime number: 31