One word names are called “mononyms”. Your example is again an example. You may have others around you with the same name but write it as Kumaran R (the initial derived from the first letter of the father’s name or the place of origin). Some may not even use an initial. These naming schemes, which are as valid as any other on the planet, have already caused a lot of trouble for people with PAN cards and Aadhaar (I recommend you read up on those if you aren’t aware).