整数按奇偶性分为两部分,其中能被2整除的整数称为偶数,通常表示为2k的形式,不能被2整除的整数称为奇数,通常表示成2k±1的形式,其中k为整数,注意:0是偶数。奇数与偶数有以下简单而又重要的性质: 性质1 奇数个奇数之和是奇数;偶数个奇数之和是偶数,偶数之和为偶数。性质2 如果若干个整数的乘积是奇数,那么其中每一个因 Integers are divided into two parts by parity, where an integer that can be divisible by two is called an even number, and is usually expressed in the form of 2k. An integer that cannot be divisible by two is called an odd number and is usually expressed in the form of 2k±1, where k is an integer , Note: 0 is an even number. Odd and even numbers have the following simple and important properties: Property 1 Odd odd odds are odd; odd sums are even and even sums are even. Property 2 If the product of several integers is odd, then each of them