First: You don't need to worry about using the slow performance code from the Raghav Sood's answer.
Second: You don't need to write an extension function provided by w3bshark's answer when using Kotlin.
Finnaly: All you need to do is to use the Kotlin android-ktx library from Google (refer here to find more information and how to include it on your project):
// Suppose id = 1111 and name = neil (just what you want).
val s = SpannableStringBuilder()
.bold { append(id) }
.append(name)
txtResult.setText(s)
Produces: 1111 neil
UPDATE:
Because I think it can help someone else as well as to demonstrate how far you can go here are more use cases.
When you need to display a text with some parts in blue and italic:
val myCustomizedString = SpannableStringBuilder()
.color(blueColor, { append("A blue text ") })
.append("showing that ")
.italic{ append("it is painless") }
When you need to display a text in both bold and italic:
bold { italic { append("Bold and italic") } }
In short, bold, append, color and italic are extension functions to SpannableStringBuilder. You can see another extension functions in the official documentation, from where you can think for other possibilities.