Pinyin: hé shù detailed explanation 1. This is reasonable. "A Brief Training of Huainan Zibing": "When you make a statement, you must combine your words, move them, and solve them." In the Southern Dynasties, Liang Liu Xie wrote "Wen Xin Diao Long: Ti": "Although the eight bodies are different, they must be combined. If they are in the ring, they must be combined." 2. Mathematical terminology. A number in which there are other factors besides 1 and itself. For example, 6 can be divisible by 1 and 6, or by 2 and 3. Xu Chi Goldbach Conjecture 3: "The teacher said that you all know even and odd numbers, as well as prime numbers and composite numbers." In other words, if a number is divisible by 1 and other factors besides itself, then it is called a composite number.

Edit the concept of composite number in this paragraph.

Composite number means ① the greatest common factor between two numbers is only the product of those two numbers1; ② The common divisor between two numbers is not only 1. Multiplying a divisor by the smallest number can be divisible. The multiplied number is a composite number, also known as a composite number, which is a positive integer satisfying one of the following (equivalent) conditions: 1. It is the product of two integers greater than 1; 2. There is a factor)； greater than 1 and less than itself; 3. There are at least three factors (factors); 4. It is neither 1 nor a prime number (prime number); 5. Incomplete numbers with at least one prime factor. 6. The product of two or more prime numbers can form a composite number, and only a composite number can be formed. On the contrary, a composite number can be divided into a product of a group of prime numbers, and only into a product of a group of prime numbers. That is to say: the composite number formed by the product of more than three prime numbers cannot be regarded as the product of two prime numbers! (It can also be said that there are other factors besides 1 and itself. ) 7. Composite number means that a number has other factors (the third factor) besides 1 and itself. This number is called a composite number. 8. "0" and "1" are neither prime numbers nor composite numbers. 9. An integer whose divisor can be divisible by factors other than 1 is called a composite number. The complex number 4.6.8.9.10.12.14.16.18. 80.8 1.82.84.85.86.87.88.90.9 1.92.93.94.95.96.98.99. 100。 ***74.

Edit this merge series.

Among natural numbers, we call those numbers divisible by 2 even numbers, such as 2, 4, 6, 8, 10, ... and so on. The remaining natural numbers are called odd numbers, such as 1, 3, 5, 7, 9, ... and so on. In this way, all natural numbers are divided into even numbers and odd numbers. On the other hand, besides 1, some numbers are not divisible by other integers besides 1 and itself, such as 2, 3, 5, 7,1,13, 17, etc. This number is called. All the prime numbers except 2 are odd numbers. Some numbers can be divisible by 1 and other integers other than itself. This number is called a composite number, such as 4, 6, 8, 9, 10, 12, 14, ... and so on, this is a composite number. Odd numbers include plural numbers (such as 9, 15, 2 1, etc.). All even numbers except 2 are composite numbers. 1 is a special number. It is neither a prime number nor a composite number. In this way, all natural numbers are divided into 1, prime numbers and composite numbers. Series like 4, 6, 8, 9, 10, 12, 14, ... are called classic multiple-choice questions 256,2 1 6,64,9,1. () A. 114b.1/2c.11/d.1/. 12 analysis: 4 times 6 times 3 times 8 times 2 times 9 times 1 times 10 times 0 times Considering that 4, 6, 8, 9 and 10 are all complex numbers, the next space should be B.11. When the first term is not a prime number, the series is a compound series.

Edit the comprehensive figures of Mei Sen in this paragraph.

Mei Sen complex decomposition is very difficult, and modern computers are often used to test the performance of computers. Mei Sen's complex decomposition has made some insignificant progress: 1, p=4r+3. If 8r+7 is also a prime number, then: (8r+7) | (2 p- 1). That is, (2p+1) | (2p-1); For example: 23 | (211-1); ; 1 1=4×2+3; 47|(2^23- 1); ; 23=4×5+3; 167|(2^83- 1); ,,,.83=4×20+3; . . . . 2, p = 2n× 3 2+1,then (6p+ 1) | (2 p- 1), for example: 223 | (2 37-1); ; 37=2×2×3×3+ 1; 439|(2^73- 1); 73=2×2×2×3×3+ 1; 3463|(2^577- 1); ; 577=2×2×2×2×2×2×3×3+ 1; 3, p = 2 n× 3 m× 5 s- 1, then (8p+1) | (2p-1); . For example; 233|(2^29- 1); 29=2×3×5- 1; ; 1433|(2^ 179- 1); 179=2×2×3×3×5- 1; 19 13|(2^239- 1); 239=2×2×2×2×3×5- 1; There are still some progress in the decomposition of Mason number, so I won't describe them one by one.