Showing what's behind the curtain

Find Fibonacci numbers for which the first and last nine digits are pandigital.

Find the sum of all 1-9 pandigital numbers that is composed of two factors and their product.

What is the largest 1 to 9 pandigital that can be formed by multiplying a fixed number by 1, 2, 3, … ?

Find the largest n-digit pandigital prime that exists