Concept for Natural Numbers

Natural numbers: Natural numbers are the numbers used for counting and begin from 1 onwards.
They are denoted by the set: N = {1, 2, 3, 4, 5, …}

1. The first and the smallest natural number is 1 (one)
2. The last and the greatest natural number can not be obtained. [infact, there are infinite natural numbers, like counting the stars in nature.] 
3. The difference between any two consecutive natural numbers is 1 (one). 
4. By adding 1 to any natural number, its next natural number is obtained. 
5. The fractions, like  `"3"/"4"` , – `"12"/"17"` etc., are not natural numbers.
6. The decimal numbers like 3.4, 5.28, 2.227, etc., are not natural numbers. 
7.0 (zero) is not a natural number. 
8. No natural number is negative, i.e. none of -15, -3, -214, etc., is a natural number. 
9. If n is any natural number :
(i) 2n is an even natural number and
(ii) (2n - 1) is an odd natural number.