This sample compares countries by population density and total area by using various radius in pie series.
In this example, you can see how to render doughnut chart with different radius. You can use radius mapping property to achieve this feature. dataLabel is used to represent individual data and its value. In addition, the sample shows how to shift the order of the legend for the doughnut chart by using the reverse property.
Tooltip is enabled in this example, to see the tooltip in action, hover a point or tap on a point in touch enabled devices.
More information on the pie series can be found in this documentation section.