Prime number "according to the definition of prime number, when we judge whether a number n is a prime number, we just need to use 1 to n-1 to remove N and see if it can be divisible According to the definition of prime number, when judging whether a number n is a prime number, we just need to use 1 to n-1 to remove N and see if it can be divisible. But we have a better way. First, find a number m so that the square of M is greater than N, and then use 1993. Then we just need to use 1993 to remove it

Prime number "according to the definition of prime number, when we judge whether a number n is a prime number, we just need to use 1 to n-1 to remove N and see if it can be divisible According to the definition of prime number, when judging whether a number n is a prime number, we just need to use 1 to n-1 to remove N and see if it can be divisible. But we have a better way. First, find a number m so that the square of M is greater than N, and then use 1993. Then we just need to use 1993 to remove it

There is a theorem: if a positive integer n is prime, there must be a divisor not greater than the root n
It is proved that if n = PQ, where p, Q > = 2, then p and Q must be one big and one small