Rafi is 37 years old; Dave is 23. This may be a joke on the movie's title, as 37 and 23 are both prime numbers (i.e., numbers that are divisible only by themselves and by 1). In real life Uma was 35, Bryan was 27
The dog sitting at Meryl Streep's feet as she is eating the pastrami sandwich with her husband is, in fact, her own dog - Digby.
Sandra Bullock was originally cast as Rafi. Bullock wanted major script changes from writer/director Ben Younger but when he refused, she dropped out. Only two weeks before principal photography, Uma Thurman stepped in and replaced Bullock.
Like his character David Bloomberg, Bryan Greenberg was born to psychologists Denny and Carl Greenberg, he has a younger sister, Becca and, he was raised in Conservative Judaism.
Was originally rated R by the MPAA but re-rated PG-13 on appeal.