A Priming Pan

An $n$-digit number is said to be pandigital if it uses all the digits from $1$ to $n$, both inclusive, exactly once. For example, a $4$-digit pandigital number is $2134$ since it uses all the digits from $1$ to $4$ exactly once. Your task is to find the largest pandigital number below a million which is also prime. If no such number exists, output a $1$. Since the result can be large, output you