使用R分析条目，如果是数字，则删除后缀

I'm a beginner in R programming language, and I'm using RStudio to work on this project I have. My dataframe has a column for the zone of the mall, but some zones are actually subzones of a bigger zone, so they are called something like: Ikea 1, Ikea 2, Ikea 3, etc. I want to create a new column with the bigger zone for each entry. I'm a beginner in R programming language, and I