9 All the men assigned to the camp of Judah, according to their divisions, number 186,400. They will set out first.

Read Numbers 2:9 Using Other Translations

All that were numbered in the camp of Judah were an hundred thousand and fourscore thousand and six thousand and four hundred, throughout their armies. These shall first set forth.
All those listed of the camp of Judah, by their companies, were 186,400. They shall set out first on the march.
So the total of all the troops on Judah’s side of the camp is 186,400. These three tribes are to lead the way whenever the Israelites travel to a new campsite.