In honor of JK Rowling’s first post-Harry Potter novel, here are three factoids:

1. The Harry Potter series sold 450 million books. That’s 450,000,000.

2. JK Rowling has (according to the London Times) a personal fortune of 900 million dollars. That’s 900,000,000. (Quick, do the math! How much is that per book??)

3. Of all her books, JK Rowling feels that Book VI, Harry Potter and the Half-Blood Prince, was the most rushed, and might have used a bit more editing.

These factoids come from the October 1, 2012 edition of The New Yorker–and from my friend Lorna, who gave me her copy since I’m too cheap to subscribe.