3343

This number is a prime.

The first prime mentioned in The Five Hysterical Girls Theorem, Rinne Groff's comeuppance for the fifth grade teacher who threatened to flunk her in math. The cutesy name for the theorem comes from the fact that (when written in the right font) certain prime numbers look like "eeheeheee" when viewed upside down.

The smaller in the first set of two consecutive emirps (also consecutive primes) whose sum of digits have the same property, i.e., 13, 17. [Sariyar]

3343 is the smallest symmetric prime that is not in the component of the symmetry graph that contains 3. [Kalmynin]