A positive integer \(n \) is called fair if the sum of the factorial of its digits is divisible by itself. 145 is one such number : \[1! + 4! + 5! = 145 \equiv 0 \mod (145) \] Find the sum of all the fair numbers less than \(10^7\).
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, conceptual quizzes.
Our wiki is made for math and science
Master advanced concepts through explanations,
examples, and problems from the community.
Used and loved by 4 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!