TITLE: What is a number theory book I can read in bed?
QUESTION [5 upvotes]: I am looking for a good book that is very easy going but not a "pop science" account i.e. something that goes through theory that would be on a basic undergraduate course for someone who finds the subject interesting but doesn't really care about total rigor. I missed a lot of the basics was I began my undergraduate in physics and to this day I have a hard time remembering what a number field is, but I find a lot of the stuff "cool". Like there are no rational points on a circle of radius 3? that's great, I only learned this yesterday! I want to learn more things like this, I can totally use this at parties!

REPLY [2 votes]: André Weil's Number theory for beginners is short and wonderful.
For a longer text, try A Friendly Introduction to Number Theory by Joseph H. Silverman.
But I wouldn't read an interesting number theory in bed: I'd be itching to get up and try some examples and write some code to test conjectures and bring theorems out to life.