Any number which is divisible by 2 is called as an Even number, and any number which is not divisible by 2 is called an Odd number. Examples of Even numbers are all multiples of 2 such as 2,4,6,8,10 .. and Odd numbers are 1,3,5,7,9,..

Any number which cannot be divisible by any other number except one and itself is called a prime number. In other words, any number which doesn't have more than 2 factors (1 and itself) is called a prime number.
Examples: 2, 3, 11, 13, 19 and such
For a given number n, we shall find out the total factors for the number and decide whether the number is a prime or not.

Factors of a given number are the numbers from 1 till the number, for which the number is divisible. It means all these numbers divide the given number and give remainder 0.
Example: The factors of 24 are 1, 2, 3, 4, 6, 8, 12, 24

The power of a given number obtained by multiplying the number with itself for a specified number of times.
For a given number a, calculate the nth power where n is any number n > 0, a > 0
Example: Func(2, 5) = 5th power of 2 = 32

Factorial of a number n can be termed as multiplication of all numbers from 1 till the number n.
n! = 1*2*3*...*n
Example:
5!=1*2*3*4*5=120