Come on, master, is there any information about composite numbers and prime numbers?

Composite number: A number has other factors besides 1 and itself, which is called a composite number.

Prime number: A number that has no other factor than 1 and itself is called a prime number.

The smallest composite number is 4

The smallest prime number is 2

Even: divisible by 2.

Odd: not divisible by 2.

So many lines?

A prime number is a divisor in all integers greater than 1, except for 1 and itself, and this kind of integer is called a prime number or prime number.

In a natural number, if there are other divisors in addition to the two divisors of 1 and itself, this natural number is called a composite number.

1 is neither prime nor composite.

The minimum sum number is 4

The concept of composite numbers: a number that has other factors (divisors) in addition to 1 and itself is called a composite number. (Except for 1, which is neither prime nor composite).

The smallest composite number is 4 (the factor is ).

The factors of a natural number have other factors besides itself and 1, so the natural number is called a composite number. The minimum composite number is 4. The factor of a natural number is called a prime number except for itself and 1, and the smallest prime number is neither prime nor composite.

The horizontal line in the middle of the fraction is called the fraction line, the number above the fraction line is called the numerator, and the number below the fraction line is called the denominator.

Characteristics of multiples of 2.

At the end of a number is 0 2 4 6 8, which is a multiple of 2.

For example, the end of 6 is a multiple of 2. 3776 divided by 2 = 1888

Characteristics of multiples of 4.

The last two digits of a number are multiples of 4, and this number is a multiple of 4.

Divide by 4 = 14, which is a multiple of 4. 2356 divided by 4 = 589

Characteristics of multiples of 5.

The end of a number is 0 5, and this number is a multiple of 5.

The end of 5 is a multiple of 5. 7775 divided by 5 = 1555

Characteristics of multiples of 8.

The last three digits of a number are multiples of 8, and this number is a multiple of 8.

Divide by 8 = 32, which is a multiple of 8. 7256 divided by 8 = 907

Characteristics of multiples of 3.

The sum of the digits of a number is a multiple of 3, and this number is a multiple of 3.

4926。(4+9+2+6) divided by 3=7, which is a multiple of 3. 4926 divided by 3 = 1642

In integers, the number divisible by 2 is even, the number not divisible by 2 is odd, the even number can be represented by 2k, the odd number can be represented by 2k+1, where k is an integer.

Decimals are made up of integer parts, decimal parts, and decimal points. When measuring an object, it is often not an integer number that is obtained, and the ancients invented decimal numbers to supplement integers Decimals are a special form of decimal fractions. The denominator is ......The fraction can be expressed as a decimal.

All fractions can be expressed as decimals, except for infinite non-cyclic decimals. Irrational numbers are infinite non-cyclic decimals.

1) Thought Process: Since prime numbers are not divisible by other natural numbers, their factors will also be 1 and themselves. For example, if 2 is a prime number, the factor of 2 will only have 1 and 2.

According to the problem, from 1 to 20, is the prime number and the product of all the factors multiplied is the largest number. From 1 to 20, the prime numbers are 2, 3, 5, 7, 11, 13, 17, 19. Because the factors of 19 are multiplied to 19x1=19.

So, the answer is 19. Equation: 19 is the prime number and the factors of 19 are multiplied by 19x1=19 so.

The product of all factors multiplied is the largest number = 19

2) All prime numbers in 1 10 = 2

7 2*3*7=42 or 2*3*5*7=210 210 5=42 So Xiang Aya missed by 5 3) Prime numbers must be odd except for 2. (In other words, 2 is the smallest prime number and the only even number).

Prime number: is a natural number greater than 1 that has no other factor than 1 and itself.

Composite: A number of natural numbers that can be divisible by other numbers (except 0) in addition to 1 and itself.

The number of prime numbers is infinite, and there must be at least one prime number between a number greater than 1 and its 2 times (i.e., in the interval [a, 2a]).

The even numbers with greater than 2 are composite numbers, and all the odd numbers with a single digit of 5 are composite numbers, and all natural numbers with a single digit of 0 are composite numbers except for 0, and all natural numbers with a single digit of 4, 6, and 8 are composite numbers.

Applications

Prime numbers are used in cryptography, the so-called public key is to add prime numbers to the information to be transmitted when encoding, and then transmit it to the recipient, after receiving this information, if there is no key owned by the recipient, then the process of decryption (in fact, the process of finding prime numbers) will be too long because of the process of finding prime numbers (decomposing prime factors), so that even if the information is obtained, it will be meaningless.

In the design of automobile transmission gears, the number of teeth of the two adjacent large and small gears is designed as prime numbers to increase the minimum common multiple of the number of times two identical teeth meet and mesh in the two gears, which can enhance durability and reduce failure.

A prime number is a positive integer that cannot be divisible by any other number except 1 and itself, also known as a prime number.

A composite number is a number of natural numbers that can be divisible by other numbers in addition to 1 and itself.

The difference between a prime number and a composite number is the number of factors, a prime number has only 2 factors, and a composite number has more than 2 factors.

Positive integers other than 1 and 0 that are not prime numbers are composite numbers. "0""1" is neither prime nor composite.

A number is divisible by other numbers besides 1 and itself, and this number is a composite number.

A number is only divisible by 1 and itself, and that number is prime.

Prime numbers are singular, and composite numbers are doubles.

A prime number is a positive integer that is not divisible by any number other than 1 and itself.

A composite number is a number in a positive integer that can be divisible by other numbers in addition to 1 and itself.

The difference between prime numbers and composite numbers is the number of factors, prime numbers have only 2 factors, and composite numbers have at least 3 factors.

"1" is neither prime nor composite.

A prime number, with only 1 and its own two divisors.

Composite, with more than two divisors.

Since 0 is now commonly regarded as a natural number in the world, (0 is a multiple of all positive integers, it makes no sense to study it, and 0 cannot be used as a divisor).

Prime number: A number that has no other factor than 1 and itself is a prime number.

Composite Number: In addition to 1 and itself, the number of other factors is a composite number.

"1" is neither prime nor composite.

Since 0 is usually regarded as a natural number in the world, and 0 is also regarded as a natural number in the National Standard, prime numbers and composite numbers are generally defined in the range of positive integers (0 is a multiple of all positive integers, it is meaningless to study it, and 0 cannot be used as a divisor).

Prime number: A number that has no other factor than 1 and itself is a prime number.

Composite Number: In addition to 1 and itself, the number of other factors is a composite number.

"1" is neither prime nor composite.

A prime prime number is a number other than one and itself. The factors of a prime number are only one and itself. And the combined number has two extra factors that can be divisible by other factors such as two, three, etc. 01 is neither prime nor composite. Use.