215

215 is a composite number and a semiprime ( = 5 × 43 {\displaystyle =5\times 43}).
215 = ( 3 ! ) 3 − 1 {\displaystyle 215=(3!)^{3}-1}.
215 is the second smallest integer (after 5) such that n 2 − 17 {\displaystyle n^{2}-17} is twice a square: 215 2 − 17 = 2 × 152 2 {\displaystyle 215^{2}-17=2\times 152^{2}}.
215 is a vertically symmetric number on a calculator display (sequence A053701 in the OEIS).