BR2049 is a movie filled with literary and biblical references. Much attention was paid to tiny details. It seems odd that no one has, to my knowledge, provided any explanation for the numeric portion of the main character's name.

Others have already covered the likely reference for the name Joe/K so I'll not go over that again.

KD6-3.7 looks like it could be a bible reference. With KD the book, 6 the chapter, and 3 to 7 the verses. But there's no book of the Bible abbreviated KD. Of course there is a reference in the film to a book of the Bible. Galatians.

The movie calls the genetic disorder that the Child / Dr. Stelline suffered from Galatians Syndrome. That's not a real condition. It's made up for the film. They could have called it anything. And the symptoms of the disease doesn't have any obvious connection to Galations, either the historical people or the book of the Bible. So why include a reference to a book of the Bible in the name of her condition? It's also the only book of the Bible mentioned in the film. I'm not Counting the oblique ring tone reference to Peter. Besides neither 1 Peter or 2 Peter has 6 chapters in it. You know what book does have 6 chapters? Yeah that's right, Galations. And if you look up Galations 6:3-7 what does it say? Glad you asked:

"If anyone thinks they are something when they are not, they deceive themselves. Each one should test their own actions. Then they can take pride in themselves alone, without comparing themselves to someone else, for each one should carry their own load. Nevertheless, the one who receives instruction in the word should share all good things with their instructor. Do not be deceived: God cannot be mocked. A man reaps what he sows."

The similarities between this passage and the film's themes are numerous. Too numerous, within such a short passage, to be coincidence.