Question

Is \[91\] a prime number?

Answer 1

Hint: In order to find whether a number is prime or composite the foremost step is to find the factors and result depends upon the number of factors. Prime number is a number that is divisible only by itself. But according to the definition of prime number: To determine if the number is a prime number, see whether \[(9 + 1)\] is divisible by three. Continue with the steps below since \[9 + 1\] equals \[10\], which is not divisible by \[3\].

Complete step-by-step answer:
In this problem,
We have to check whether the number \[91\] is prime or not.
 Find the square root of \[91\], which is \[9.53\].
 Pick a prime number less than \[9\] and see if any of them divides \[91\] evenly.
The number \[7\]divides \[91\] perfectly, as can be seen. As a result, \[91\] is divisible by \[7\].
The numbers which have only two factors, which are \[1\] and the number itself, are known as prime numbers.
A Prime number must have only two factors.
Using factor method find the factor of \[91\]\[7 \times 13 = 91\] and \[91 \times 1 = 91\]
Therefore, factors of \[91\] are \[1,7,13\] and \[91\], which are totally \[4\] factors.
 Since the number \[91\] has more than two factors we can conclude that it is not a prime number.
The factors of \[91\] are already known which are\[1,7,13,91\]. As the total number of factors of \[91\] is more than \[2\], it satisfies the condition of composite numbers.
Hence, \[91\] is a composite number.
As a result, No, \[91\] is not a prime number.

Note: In this problem, you'll learn how to find prime numbers in detail, as well as a shortcut technique. This example will show you how to quickly determine whether a given number is prime or not.
It is now well known that the number \[91\] does not fall into the category of prime numbers.
\[91\] can be included in a variety of categories, including: a natural number, a positive integer, an odd number, a rational number, a composite number, a whole number