Why is "int" convertible to "string"?

This example shows that int type is convertible to string type. But my question is why?

package main

import (
    "fmt"
    "reflect"
)

func main() {
    it := reflect.TypeOf(42)
    st := reflect.TypeOf("hello")

    fmt.Printf("%q is convertible to %q: %v\n",
        it, st, it.ConvertibleTo(st))
        // OUTPUT: "int" is convertible to "string": true

    fmt.Printf("%q is convertible to %q: %v\n",
        st, it, st.ConvertibleTo(it))
        // OUTPUT: "string" is convertible to "int": false
}

Correct me if I'm wrong. But Shouldn't this be false as well?

reflect.TypeOf(int(0)).ConvertibleTo(reflect.TypeOf("string"))

Why is “int” convertible to “string”?

Because the language spec¹ says so:

Converting a signed or unsigned integer value to a string type yields a string containing the UTF-8 representation of the integer.

1: Conversions, section "Conversions to and from a string type"