The male Levites a month old and upward totaled 23,000, though they were not included among Bnei-Yisrael, since He did not give them an inheritance among Bnei-Yisrael.
The sons of the Gershonites are to do all their tasks, whether carrying or doing other work, according to the word of Aaron and his sons. You are to assign to them all that is their responsibility to carry.