Adam Clarke on Numbers 1:25

Forty and five thousand six hundred and fifty - Mr. Ainsworth has remarked that Gad, the handmaid's son, is the only one of all the tribes whose number ends with fifty, all the others are by thousands, and end with hundreds; which shows God's admirable providence and blessing in multiplying them so, that no odd or broken number was among all the tribes. But see on Num 1:46 (note).