To build on Matthew McVeagh’s answer and comment:
Go to the renowned Zompist Numbers List.
Two and Three, *duwō and *treyes, are reasonably similar across Indo-European.
One gets conflated with Single/Same, *oynos / *sem, and ends up looking different.
Four and Five have a *kw, which went different ways in different languages, and get affected by analogy: *kwetwores *penkwe
More analogy kicks in with higher numbers, and they are less frequent to begin with as Matthew pointed out. (We have a long-standing suspicion that 7 is a loan from Akkadian, and 10 is somehow related to the word for fingers.) (EDIT: “two hands”.) But they’re still surprisingly consistent.