I have a set of consecutive natural numbers: \(B=\{1,2,3,\ldots,1728\} \). The sum of products of elements of \(B\) taken 2 or more at a time is equals to \(1729! - a \). Find the sum of digits of \(a\).

Excel in math and science

Master concepts by solving fun, challenging problems.

It's hard to learn from lectures and videos

Learn more effectively through short, interactive explorations.

Used and loved by over 6 million people

Learn from a vibrant community of students and enthusiasts,
including olympiad champions, researchers, and professionals.

Your answer seems reasonable.
Find out if you're right!