White noise analysis is providing a very strong analytical framework based on characterization theorems via analytic functions. There was an open question for 35 years by Paul Malliavin, Shinzo Watanabe and Paul-André Meyer, if the spaces in Malliavin calculus can also be characterized in a similar way. We will give a full characterization in this talk. Moreover, we show the easy applicability of the characterization on examples of SPDEs.