Challeng number: the prime numbers are the numbers that can be divided by itself and number(1)only .2,3,5,7,11,13...

Question

write program that input number .that accept prime number only and find the prime number that exist behind it .
Example 11...13

Answer 1

The correct definition of a prime number is:
A prime number is a number which has only two divisors, so 1 isn't a prime number.

Answer 2

thay are called "PRIME NUMBERS" in english