Question

what is a natural number

Answer 1

1,2,3,4,5,6....... .................


are natural no.

Answer 2

Depending on the mathematician, the natural numbers include: 1, 2, 3, 4, 5, . . . (also called the positive integers), or 0, 1, 2, 3, 4, 5, . . . (also called the nonnegative integers or whole numbers). If you are taking a mathematics class, then it is safest to ask your teacher, or look at your text, to make sure you know whether or not to include 0.

To be clear, mathematicians will sometimes use a large N to refer to the natural numbers. They may put a 0 subscript after the N if they mean for 0 to be included and a 1 after the N if they do not want the 0 included.
Hope its help!!!