1987is an odd number,as it is not divisible by 2
The factors for 1987 are all the numbers between -1987 and 1987 , which divide 1987 without leaving any remainder. Since 1987 divided by -1987 is an integer, -1987 is a factor of 1987 .
Since 1987 divided by -1987 is a whole number, -1987 is a factor of 1987
Since 1987 divided by -1 is a whole number, -1 is a factor of 1987
Multiples of 1987 are all integers divisible by 1987 , i.e. the remainder of the full division by 1987 is zero. There are infinite multiples of 1987. The smallest multiples of 1987 are:
It is possible to determine using mathematical techniques whether an integer is prime or not.
for 1987, the answer is: yes, 1987 is a prime number because it only has two different divisors: 1 and itself (1987).
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 1987). 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 44.576 ). 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: 1979
Next prime number: 1993