Not So Fast, Levi!By Rabbi Jack Abramowitz
This aliyah gives the Tribe-by-Tribe tally of the census results. All told, there were 603,550 males from the age of 20 and up in the twelve Tribes (counting Ephraim and Menashe as two Tribes and not including Levi).
Moshe was instructed not to include the Tribe of Levi in the general census since they had a special role. They (and they alone) were to be responsible for assembling and disassembling the Mishkan (Tabernacle) during its travels. The other Tribes would set up their own camps under their own banners, but the Levites were to make their camp around the Mishkan and guard its sanctity.