# Aptitude - Numbers - Discussion

### Discussion :: Numbers - General Questions (Q.No.9)

9.

Which of the following is a prime number ?

 [A]. 33 [B]. 81 [C]. 93 [D]. 97

Explanation:

Clearly, 97 is a prime number.

 Jagadeesh said: (Oct 16, 2010) Please explain, how 97 is prime number ?.

 Balram said: (Oct 22, 2010) Because it is not disible any other no.

 Divi said: (Nov 3, 2010) I can't get you.

 Sundar said: (Nov 3, 2010) A prime number (or a prime) is a natural number that has exactly two distinct natural number divisors: 1 and itself. The smallest twenty-five prime numbers (all the prime numbers under 100) are: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97. Note: 1 is not a prime number. Hope this will help you. Have a nice day!

 Monty said: (Feb 8, 2011) 2 is only even in the prime numbers.

 Niranjan Nande said: (Feb 28, 2011) Please take any perfect square near of 97 i.e 10*10=100. Now find all prime numbers which are less than 10 that are 3,5,7.Now at last check wheather 97 is divisible by 2,3,7.If it is divisible then number is not prime else it is prime.

 Ginu said: (Jan 10, 2012) 97 is a prime number.

 Deepi said: (Mar 19, 2012) I accept niranjan nandu explanation 97 is a prime number its very clear.

 Pavan.K said: (May 31, 2012) Note # 1 is neither prime nor composite number.

 Kannan said: (Nov 15, 2012) What is mean prime number?

 Lalita said: (Mar 5, 2013) Which is divisible by 1 and itself only is called prime number.

 Mubarak Dme said: (Sep 14, 2013) This is divisible by 1 and at the same time it also divisible by same number this is called prime number.

 Vishal Kesari said: (Aug 13, 2014) Because 97 is only number which is divided by one and itself.

 Viki said: (Sep 11, 2014) Because 97 is not divided by 3. Other numbers are divided by 3 so the answer is 97.

 Poorvi said: (Dec 27, 2014) 97. Nearest square = 10*10 > 97. Check if 97 is divisible by prime numbers less than 10. i.e.., 2, 3, 5, 7. If it is not divisible the given number is a prime number. Similarly for other numbers.

 Sushma said: (Jan 31, 2015) Is 93 is divisible by any numbers. Please explain?

 Khin Myat Kyu said: (May 2, 2015) 93 is divisible by 3.

 Raje said: (Jan 29, 2016) 6*6 > 33? (I know 33 is not a prime but) the formla is not appicable at all the time. So is it a wrong formula?

 Amol said: (Jan 31, 2016) 33/3 = 11. 81/9 = 9. 93/3 = 31. But 97/? not have perfect division number. 97/97 = 1.

 Venket said: (Feb 28, 2016) How to find the number of divisors, their sum and also the sum of odd and even divisors? Please help me.

 Jagadees said: (Jun 30, 2016) Is there any shortcut formulas, incase of any higher digit number as it is a two digit number?

 Rajaarasu said: (Jul 3, 2016) Excellent explanation thanks to all.

 Revathi said: (Jul 4, 2016) What is prime number? I can't Understand, Please explain it.

 Guru said: (Jul 15, 2016) Good explanation thanks to all.

 Dhiru said: (Aug 10, 2016) Find the square root of the number i.e. square root of the 97 is 9 point something Now divide the 97 by each prime less than 9 if it not divisible it will be prime.

 Madan said: (Sep 3, 2016) 3 * 11 = 33, 3 * 3 * 9 = 81, 3 * 31 = 93, But 97/3 = It's not whole number. So 97 is the correct answer.

 Pravallika said: (Sep 27, 2016) To find prime no we have to divide the number with 2, 3 & 7. Then only is it called as a prime number.

 Harish said: (Nov 27, 2016) I understand now, thanks @Viki.

 Sravani said: (Dec 11, 2016) How to identify the prime numbers easily? Please tell me I'm very confused anyone please tell me.

 Sravani said: (Jan 19, 2017) Is there any shortcut formula to solve this?

 Prasad said: (Jan 29, 2017) If a number have exactly two factors that number called prime number. ex:7 has 1 and 7 only factors so its prime number and suppose 6 has 1,2,3,6 has factors so it's not the prime number.because it should be exactly 2 factors but here 4 factors are theirs. So it's not the prime number. Hope you, understand

 Diya said: (Apr 10, 2017) Here, 7 and 13 are the factors of 97. Then how it is prime?

 Aditya said: (May 19, 2017) 31 * 3 = 93 that's why 97 is prime.

 Malik said: (Sep 15, 2017) How it is prime number?

 Deekshi said: (Oct 3, 2017) Prime Number means having only 2 factors those are 1 and it self. So 97 is a prime number.

 Yoga said: (Dec 29, 2017) A prime number (or a prime) is a natural number that has exactly two distinct natural number divisors: 1 and itself. The smallest twenty-five prime numbers (all the prime numbers under 100) are:. 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97. Note: 1 is not a prime number.

 Siddharth Daggubati said: (Mar 30, 2018) Yes, 97 is the prime number.

 Paimon Dkhar said: (Jan 13, 2019) 97 is a prime Number.

 Vidya Kharvi said: (May 9, 2021) Yes, 97 is a prime number. Because as per prime num definition i.e prime number is a number that is divisible by 1 and itself. 33 is not a prime num because it is divisible by 3, 81 is also not a prime num because it is divisible by 9, 93 is also not a prime num because it is divisible by 3 but whereas 97 is not divisible by any other num expect 1 and itself so, 97 is a prime number.