7. The sum of the first $n$ terms of an arithmetic sequence is 2000, the common difference is 2, the first term is an integer, and $n>1$, then the sum of all possible values of $n$ is $\qquad$ .
7. 4835.

Slightly solved: Let the first term of the sequence be $a_{1}, a_{1} \in \mathbf{Z}$, common difference $d=2$, and the sum of the first $n$ terms be $S=\frac{\left(a_{1}+a_{n}\right) n}{2}=(a+n-1) n=2000$.

Since $2000=2^{4} \cdot 5^{3}$, the value of $n$ is a divisor of 2000, so the sum of all possible values of $n$ is $(1+5+$ $25+125)(1+2+4+8+16)-1=4835$.