What is a prime number?
A prime number is the number
which can be evenly divided by itself or the number one. It has to be a whole
number which is greater than the number one. Whenever you find that you are not
able to divide the number evenly you know it is a prime number. In case of extremely big numbers we can take
the help of computers to test if it is a prime number. At times it has been
seen for really big numbers, even for super computers it becomes a mammoth task
to determine if it is actually a prime number. In practical life a lot of
internet securities are based on mathematics just by using prime numbers.
Examples of prime numbers
There are many examples of prime
numbers few of which are 2, 3, 5,7,11, 13, 17, 19, 23, 29 etc. As we continue the
series the prime numbers turns out to be less frequent. But there is no such
prime number which you can say is largest. Zero is not considered as a prime
number. Long time back the number one was considered as prime number but it
recent times it is no longer considered the same.
How to make out if a number is actually a prime number?
To decide if a particular number
is a prime number or not we have to check if any digit can evenly divide that
number. The square of that number also helps us in checking if at all it is a
prime number. Supposing, we take into consideration the number ‘15’ and try to
check if it is a prime number. Firstly we have to give a try and see if the
number 2 can evenly divide it. Since 2 cannot divide 15 evenly we have to then
next try to divide it evenly with the number 3. And yes 3 can divide 15 very
easily as 3x5=15. This is the reason why checking the square root of a given
number helps in determining if that particular number is a prime number.
Is 39 a prime number?
The answer to this particular
question i.e. “is 39 a prime number?” isno.
The number 39 is not considered as a prime number, as 39
can be divided not only by the number one and itself but also by the numbers 3
and 13. A whole number which can be evenly divided by other numbers except for
the number one and itself are known as composite numbers. Therefore here 39 is
a composite number. Composite numbers are basically made up of the prime
numbers together multiplied. This is the reason as to why those numbers are
called composite numbers as the term composite means “something which is made
by combining some other things”. The number one is neither a prime number nor a
composite number.
So by now the definition of prime
and composite numbers must be clear and therefore one can easily determine if a
particular number is prime or composite. And also you must have got your answer
to the query i.e. “is 39 a prime number?”
No comments:
Post a Comment