conditional statement for logical output

I want to modify the following R code based on the logical output of the function.

is_x_prime = function(x){
  vapply(x, function(z) sum(t / 1:t == t %/% 1:t), integer(1L)) == 2L
}

so that if the output is:

  if(TRUE)
   { cat("The number", x," is prime.")}
   else
   { cat("The number", x," is not prime.")}

I was not able to combine them.

Thanks