Numbers 2:32
31 All those numbered of the camp of Dan are 157,600. They will travel last, under their standards.” 32 These are the Israelites, numbered according to their families. All those numbered in the camps, by their divisions, are 603,550. 33 But the Levites were not numbered among the other Israelites, as the Lord commanded Moses.
2 Samuel 24:8
8 They went through all the land and after nine months and twenty days came back to Jerusalem. 9 Joab reported the number of warriors to the king. In Israel there were 800,000 sword-wielding warriors, and in Judah there were 500,000 soldiers. 10 David felt guilty after he had numbered the army. David said to the Lord, “I have sinned greatly by doing this! Now, O Lord, please remove the guilt of your servant, for I have acted very foolishly.”
Notes and References
"... Six hundred three thousand five hundred fifty ... Add to this the underage and elderly men, the women of all ages, and the Levites, and the total number of Israelites must approach two million. It has been calculated that by these numbers, marching eight across, when the first Israelites reach Mount Sinai, half of them would still be in Egypt! The extraordinary size of this population is a famous old problem in traditional and critical biblical scholarship. The numbers appear far too high; but they do not appear to be entirely invented, either, because what would be the motive for contriving them in all of this tribe-by-tribe detail for the first four chapters of Numbers? Some suggest that the word for 'thousand' here means rather a 'clan', but that is not correct. One possibility is that these are the numbers from the census that is attributed to King David (2 Samuel 24). Coming centuries later, in a period in which Israel is settled in the land, the numbers are more understandable in the Davidic era (though they are questionably high even for that period). In this scenario, the records here would have come from old documents among the archives which would have come to be mixed in with documents that were used as sources for the Torah ..."
Friedman, Richard Elliott Commentary on the Torah: With a New English Translation (pp. 1122-1123) Harper Collins, 2003