783 Followers Problem

Number Theory Level 2

$a(a+b)(a+b+c)(a+b+c+d)=783$

Given that $a,b,c,d$ are positive integers and that they satisfy the above equation, find their product: $a \times b \times c \times d$ .

This is part of the set Trevor's Ten

Based off of one of Sualeh Asif's posts.