The first 49 prime numbers 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, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, and 227.

Now, we can observe that the greatest two digit prime number is 97. So, the correct answer is “97”. Note: The greatest two digit natural number is 99. But 99 is not a prime number because it has factors 1, 3, and 9.

Zero can never be a prime number as it can be divided by 1, and any other number. It has an infinite number of divisors and therefore doesn’t meet the definition.

Find out square root on N. Traverse all odd numbers up to the sqrt(N) and try to devide the N with current odd number. If remainder is 0 for any odd number then number is NOT PRIME. Else – number is PRIME.

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, For example, 5 is a prime number because you can divide 5 by 1 evenly and divide 5 by 5 without a remainder, but if you divide 5 by any other integer, you get a remainder. Now look at the number 4 which is not a prime.

Pseudocode

1. INPUT n.
2. i = 2.
3. answer = prime.
4. WHILE i <= n / 2.
5. rem = n % i.
6. IF rem is not equal to 0.
7. i = i + 1.
8. ELSE.

Prime number in Java: Prime number is a number that is greater than 1 and divided by 1 or itself only. In other words, prime numbers can’t be divided by other numbers than itself or 1. For example 2, 3, 5, 7, 11, 13, 17…. are the prime numbers.

To find a prime number in Python, you have to iterate the value from start to end using a for loop and for every number, if it is greater than 1, check if it divides n. If we find any other number which divides, print that value.