To determine if 1980 is a prime number or a composite number, we simply look at the factors for 1980.
If the factors of 1980 are only 1980 and 1, then we know that 1980 is a prime number. Otherwise, 1980 is a composite number.
To explain better, if 1980 is only divisible by 1 and 1980, then it is a prime number, and if 1980 is divisible by more than 1980 and 1, then it is a composite number.
The factors of 1980 are as follows:
1, 2, 3, 4, 5, 6, 9, 10, 11, 12, 15, 18, 20, 22, 30, 33, 36, 44, 45, 55, 60, 66, 90, 99, 110, 132, 165, 180, 198, 220, 330, 396, 495, 660, 990, 1980
Therefore, since 1980 is divisible by more than one and itself, the answer to the
question "Is 1980 prime or composite?" is highlighted in blue below.
composite
Is 1981 prime or composite?
OK. Now you know that 1980 is a composite number. Use our logic above and see if
you can figure out if the next number on our list is prime or composite before you check your answer.
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