只有 1和它本身两个约数的自然数叫做质数(也叫素数 ) .由此定义不难得到质数的一条性质 :若P是质数 ,m、n均是正整数 (mn)且 mn=P(或P2 ) ,则有 m=1,n=P(或 P2 ) .这个性质虽然简单 ,但在处理某些问题时 ,却能大显身手 .现举数学竞赛题为例说明如下 :例 1　 m、n为自然数 ,且 A natural number of only 1 and its two divisors is called a prime number (also called a prime number). This definition makes it difficult to get a property of a prime number: if P is a prime number, m and n are both positive integers (mn) and mn=P (or P2), then there is m = 1, n = P (or P2). Although this property is simple, but in dealing with some problems, but it can show their talents. Now take the math contest as an example to illustrate: Example 1 m, n is Natural number, and