What is the (1) prime number of primary school mathematics? What is a prime number? (2) What is an odd number? What is an odd number? (3) What is an even number? What is an even number?
Prime number: The divisor is only 1 and its own number 3. Prime numbers two, three, seven, 47, 53. Among the integers, the number that is not divisible by 2 is odd, and the odd number can be represented by 2k- 1 (k is an integer). 1, 3,7,47,53. In an integer, the number divisible by 2 is even, such as 2, 18, 78, 90, 98.