In the following video, Motley Fool financial analysts Matt Koppenheffer and David Hanson look at one very big number from Berkshire Hathaway's (BRK.A -0.20%) (BRK.B -0.06%) 10-K filing on Friday: the company's total year-end employment. Matt gives us this staggering figure compared with the size of other well-known companies and discusses how the range of companies and subsidiaries under the Berkshire name essentially means that owning Berkshire stock is comparable to owning a mutual fund. Finally, he notes some things about the company's corporate leadership structure that make it an attractive investment.