It's not, it wouldn't make sense to have 100,000 tokens just for the first 100,000 numbers. There's a playground [1] where you can see how LLMs tokenize a string.
12345678987654321 is tokenized on various models like so:
GPT4 123-456-789-876-543-21
GPT3 123-45-678-98-765-43-21
Llama-2, Mistral 1-2-3-4-5-6-7-8-9-8-7-6-5-4-3-2-1