1997is an odd number,as it is not divisible by 2
The factors for 1997 are all the numbers between -1997 and 1997 , which divide 1997 without leaving any remainder. Since 1997 divided by -1997 is an integer, -1997 is a factor of 1997 .
Since 1997 divided by -1997 is a whole number, -1997 is a factor of 1997
Since 1997 divided by -1 is a whole number, -1 is a factor of 1997
Multiples of 1997 are all integers divisible by 1997 , i.e. the remainder of the full division by 1997 is zero. There are infinite multiples of 1997. The smallest multiples of 1997 are:
It is possible to determine using mathematical techniques whether an integer is prime or not.
for 1997, the answer is: yes, 1997 is a prime number because it only has two different divisors: 1 and itself (1997).
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 1997). 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 44.688 ). 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: 1993
Next prime number: 1999