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# Prime Numbers

A natural number greater than one that is divisible by only 1 and itself, is known as a prime number. A prime number has no divisor other than 1 and itself. In other words, if a number "x" is a prime number than it has to be greater than 1 and is divisible by only 1 and x.

For example: 7 is a prime number because it is greater than 1 and is divisible only by 1 or 7.
9 is not a prime number, since it is divisible by 3.

Few prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37 ...........
The property of a number to be prime is known as primality.

Properties of Prime Numbers
Prime numbers have few important properties which are described below:

• There are infinitely many prime numbers.
• 1 and 0 are not categorized as prime numbers.
• There is no even prime number other than "2", because even numbers except 2 are divisible by 2 and hence are not considered as prime numbers.
• There is no prime number that ends in 5 and is greater than 5, because a number greater than 5 that ends in 5, is divisible by 5 and hence it is not a prime number.
• A prime gives zero remainder, only when divided by 1 or itself.
• The natural numbers greater than 1 and are not prime, are known as composite numbers.
• Every natural number can be represented in the form of product of prime numbers which is known as prime factorization. Prime factors for a particular number are unique.
• The set of prime numbers is a subset of natural numbers as well as integers and hence it is a subset of real numbers too.

 Related Calculators Calculate Prime Number Calculate Prime Factors Find Prime Factorization Calculator Prime Factorization Tree Calculator

 More topics in  Prime Numbers Properties of Prime Numbers How to Find Prime Numbers Examples of Prime Numbers List of Prime Numbers
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