18的因數(shù)中,________既是奇數(shù),又是合數(shù),________既是偶數(shù)又是質(zhì)數(shù).
9 2
分析:18的因數(shù)有1、2、3、6、9、18,根據(jù)奇數(shù)和合數(shù)的定義得到既是奇數(shù),又是合數(shù)的數(shù)是9,根據(jù)偶數(shù)和質(zhì)數(shù)的定義得到既是偶數(shù)又是質(zhì)數(shù)的數(shù)是2.
解答:18的因數(shù)有1、2、3、6、9、18,
9既是奇數(shù),又是合數(shù),2既是偶數(shù)又是質(zhì)數(shù).
故答案為:9,2.
點評:此題考查了合數(shù)與質(zhì)數(shù)及奇數(shù)與偶數(shù)的初步認識,本題是綜合題型,屬于中檔題型.