This a self-test problem for physical chemistry. Carbon monoxide is a poisonous gas because it binds strongly to hemoglobin, preventing the transport...

This a self-test problem for physical chemistry. 

Carbon monoxide is a poisonous gas because it binds strongly to hemoglobin, preventing the transport of oxygen by blood. The bond in a 12C16O molecule has a force constant of 1860 N/m. Calculate the vibrational frequency, v, of the molecule and the energy separation between any two neighboring vibrational energy levels. 

I used the equation:  v= 1/2pi*(force constant/reduced mass)1/2  I got 6.860 g which I converted to kg. . The answer in the book is 64.32 THz but I don't understand how they got it.