the number seventeen

The number 17 holds various cultural and mathematical significance. In ancient Urartu, 17-fold sacrifices were made to a deity. The biblical Flood began and ended on the 17th day of consecutive months. Greek superstition suggests the 17th day is optimal for building boats. For mathematicians, 17 is notable because a regular 17-sided polygon can be constructed using only a ruler and compass, a discovery made by Carl Friedrich Gauss.1

Seventeenth can also refer to the 17th item in a series or one of 17 equal parts of something. In music, it denotes an interval spanning two octaves and a third, or an organ stop that produces notes 17 diatonic degrees higher than those played.2