**Q: **Is a 2 easily tested by merely looking at the last digit? ¶

**A: **Yes.

**Q: **Is a 2 identified with the set {{∅},∅}? ¶

**A: **Yes, This latter set is important in category theory: it is a subobject classifier in the category of sets.

**Q: **Is a 2 the first Sophie Germain prime? ¶

**A: **Yes, and the first factorial prime, the first Lucas prime, the first Ramanujan prime, and the first Smarandache–Wellin prime.

**Q: **Was a 2 the first known irrational number? ¶

**A: **Yes.

**Q: **Is a 2 the position of the catcher? ¶

**A: **Yes.

**Q: **Is a 2 important in Judaism, with one of the earliest references being that God ordered Noah to put two of every unclean animal in his ark? ¶

**A: **Yes, Later on, the Ten Commandments were given in the form of two tablets.