A handful of numbers have a very special property: you can add their digits together and divide the original number by their total without a remainder. And why does it matter? Well, in terms of mathematics, it's mostly a curiosity. Dattatreya Ramchandra (D. R.) Kaprekar saw these numbers as sparking joy in the mind, so he named them "Harshad" numbers, with harshad being the Sanskrit word for joy. And it's an important lesson about numbers: not every bit of math needs to change the world. Something that makes you go "huh" for a brief moment can be enough.