Using R, I need to create a code that checks whether a number x is a prime number or not using RECURSION ONLY (while, for, and any iterative operators are not allowed. I made one but it seems that my...

Using R, I need to create a code that checks whether a number x is a prime number or not using RECURSION ONLY (while, for, and any iterative operators are not allowed. I made one but it seems that my code has a problem when I run it :

is_prime <- function="" (x)="">

  divisor <->
  divisor_check <- function="" (x,="" divisor)="">
    if (x <= 2)="">
      if (x == 2){
        return(TRUE)
      } else {
        return(FALSE)
      }
    }
    else if (x %% divisor == 0) {
      return(FALSE)
    }
    else if (divisor * divisor > x) {
      return(TRUE)
    } else if (x == 0 || x != floor(x)){
      return(NULL)
    }
    else {
      return(FALSE)
    }
  }

  divisor_check(x, divisor+1)
}

above is the code and when I run it, the results are as follows:

> is_prime(1)

[1] FALSE

> is_prime(2)

[1] TRUE

> is_prime(3)

[1] FALSE

> is_prime(4)

[1] TRUE

> is_prime(5)

[1] TRUE