Answer
The name of the amine is $butylmethylpropylamine$.
Work Step by Step
Amines are named according to the hydrocarbon groups attached to the nitrogen, and the ending is assigned $-amine$. Here, the three hydrocarbon groups attached to the nitrogen atom are -methyl, -butyl and -propyl. Hence, the name of the amine is $butylmethylpropylamine$ (the hydrocarbon groups are named alphabetically).