A megahertz is one million (or 106) hertz. See hertz, kilohertz (one thousand hertz), gigahertz[?] (109 hertz), terahertz[?] (1012 hertz), and petahertz[?] (1015 hertz).
... 3.42 and the average family size is 3.67. In the town the population is spread out with 30.3% under the age of 18, 8.1% from 18 to 24, 29.9% from 25 to 44, 23.8% from 45 ...