What is prime number and odd number.

All Prime numbers except 2 are odd numbers.

Now a prime number can only be divided by 1 and itself. For eg. 2,3,5,7,11,13,17, etc.

Whereas odd number cannot be perfectly divided by 2 without leaving remainder 1.

The general formula for odd number is 2n-1 where n€natural numbers.

If an odd number is not a prime number then that odd number has extra divisible factor except 1 and itself. For eg. 9 is odd but not a prime. So it has extra factor i. e. 3. Similarly, 15 has 3 and 5.

Odd number can be expressed as product of primes or sometimes can even be equal to prime number.