She lives in house number 171:

The first scene Beck and Joe have together, Joe recommends the book “Desperate Characters” by Paula Fox:

Joe Goldberg lives in apartment 4b, which can be construed as either 42, since b = 2nd letter, or 425 since b =25 in reverse ordinal. In reverse reduction, b = 7, so it can also be 47…

The bookstore where Joe works has a book opening sale or something, where the featured book is Doctor Sleep:

This book published 1811 days before the airing date of the show:

This flight is 47 days after the first episode aired: