Day 25

# 25 of 100: Life, the Universe, and Everything

The positive number $\color{#D61F06}X$ is divisible by 42, and is composed of only 1s and 0s when written in base 10. What's the smallest number that $\color{#D61F06}X$ might be?

If you don't know where to begin, take a peek at the divisibility rules on this page.