string

From The K Language Wiki
String
$x

The string function, generally denoted by $, converts atoms to their string equivalents.

The string primitive is right atomic and $ on a character is the equivalent of enlisting it, except in kona, oK, k7, and k9 where character lists are treated as if they are atoms.

  $120 4
("120";,"4")
  $`beef
"beef"