The analysis, performed by the Gadbury Group for Businessweek.com, was based on average household income ($331,840 in Gladwyne) and average household net worth ($1,483,586 in Gladwyne).
The number of households in the 100 richest zip codes grew by 7.4 percent from 2000 to 2011, according to the analysis.
During that same time period, the number of households in Gladwyne (19035) grew by about 2.5 percent to 1,495 households, states Businessweek.com.
"Once a summer destination for wealthy Philadelphians, Gladwyne, on the Schuylkill River, has become a wealthy year-round community," reads the Businessweek.com profile. "The predominant group in this Zip Code is elite couples and singles."
Villanova (19085) was identified as the No. 30 richest zip code, with an average household income of $270,720 and an average household net worth of $1,353,580.
The percentage change in the number of households in Villanova between 2000 and 2011 was about 1.5, according to Businessweek.com.
The richest zip code was identified as Palm Beach, Fla. (33480).
Take a tour of some million-dollar homes that have been profiled on Bryn Mawr-Gladwyne Patch: