Dividing by $2016!$ you get
$$\frac{2017}{1+\frac{1}{2016}+\frac{1}{2016\cdot 2015}+\cdots+\frac{1}{2016!}}$$
Now consider
$$\frac{2017}{1+\frac{1}{2016}}=2016$$
This implies that the full expression is smaller then $<2016$,and we have that
$$\frac{2017}{1+\frac{1.1}{2016}}>2015$$
The sum of the rest of the terms is
$$\frac{1}{2016\cdot 2015}+\cdots+\frac{1}{2016!}<\frac{1.1}{2016}$$
This could be seen easily since each term gets around $10^{-3}$ times smaller.
Hence the result is $2015$
NOTE: The $1.1$ was arbitrary,it's easy to prove and easily satisfies the inequality