Because you can know if your answer will be a whole number when you divide.
But you do know the factors of prime numbers. Every prime number has two factors: one and the number itself.
Knowing the divisibility rules will help you by being able to recognize if a number has factors (other than one and itself) which are covered by the rules. This will save actually having to start doing divisions.
7 is a prime number!
A Prime number is a number that is not divisible into whole numbers, except by itself and one. 135 is not a prime number as it is divisible by 5 with a ressulting quotient of 27.
109 is a prime number.
But you do know the factors of prime numbers. Every prime number has two factors: one and the number itself.
It important that 1 is not prime because a quote says: "A prime number is a natural number that has exactly two different natural number factors. and so i say 1 is not a prime because a prime number has 2 factor 1 and it self and 1 dose not.
A prime number can never be composite in any case. There is an exception for 2 which is both.
It is not possible to answer the question without knowing what is missing between "of" and "and" in the question and also the value of Y.
There are several so there is no way of knowing which ONE you mean.
First write a program to generate the prime number. After one prime number was generated, divide the big int number by the prime number. If the remainder is zero then quotient is the second prime number ( also it is important to check whether the quotient is prime number or not because sometimes you will get wrong answer). Repeat the process until you get the result.
Well, darling, number 19 is as prime as a fine wine. It can't be divided by anything other than 1 and itself, making it a prime number. So, rest easy knowing that 19 is standing strong in the prime club, not messing around with any composite nonsense.
The most important concept is that, apart from their order, the prime factorisation of any number is unique. This is known as the Fundamental Theorem of Arithmetic.
Composite numbers.
Knowing the divisibility rules will help you by being able to recognize if a number has factors (other than one and itself) which are covered by the rules. This will save actually having to start doing divisions.
You is called a prime number!You is called a prime number!You is called a prime number!You is called a prime number!
A prime number is a number that has exactly two factors: 1 and itself. All whole numbers greater than 1 are either prime numbers or can be written as the product of prime numbers. There are an infinite number of prime numbers, but they occur less frequently among larger numbers. Prime numbers are important in cryptography and number theory.Read more: http://wiki.answers.com/Q/FAQ/7008#ixzz1LVq5EURw