1

This number is a unit (so is neither prime nor composite).

Just showing those entries submitted by 'Worrom': (Click here to show all)

1-digit nonprime solutions using all of the 1-digit primes: [7+3/5*2] = 1; [7-5-3+2] = 1; [7+5/3!*2] = 1; [5*3-7*2] = 1. [Worrom]