TIL there are happy (and sad) numbers
https://en.wikipedia.org/wiki/Happy_number
#til #todayilearned
https://www.reddit.com/r/todayilearned/comments/1gp0l6o/til_there_are_happy_and_sad_numbers/
https://en.wikipedia.org/wiki/Happy_number
#til #todayilearned
https://www.reddit.com/r/todayilearned/comments/1gp0l6o/til_there_are_happy_and_sad_numbers/
