Type in a number to see if it's a Smith Number. In case you don't know what a Smith Number is, it is kind of complicated to explain. I'll use 666, which is a Smith Number, to explain: 666's Prime Factors are: 2, 3, 3, and 37. 6+6+6 = 18 2+3+3+3+7=18 Therefore, 666 is a Smith Number.
If you still don't understand, here's a link to the Numberphile video on Smith Numbers: https://www.youtube.com/watch?v=mlqAvhjxAjo NOTE: If you put in a really big number, it can take up to 10 minutes for this to calculate that it is, or isn't, a Smith Number, so BE PATIENT!