Deb, in Jane's body, and testing out her new brain says, "What's the square root of 113? It's a prime number. Trick question." A prime number is just any positive natural number evenly divisible only by itself and 1. The square root of number X is a number which, when multiplied by itself equals X. The square root of 25 is 5, of 100 is 10, of 113 is 10.6301458.
When the audience is introduced to Jane, the song playing is "Big Girls Don't Cry" by the Four Seasons. During the ending - where Jane is now inhibited by Deb - the song playing is "Big Girls Don't Cry" by Fergie.