Fix README.md typo

Funnily enough, this error is also in the published paper

README.md

@@ -119,7 +119,7 @@ Papers + some implementation notes:
 - When working with images, we pick the identity permutation πi = i for 1 ≤ i ≤ n, also known as raster order.
 - we create our own 9-bit color palette by clustering (R, G, B) pixel values using k-means with k = 512.
 - Our largest model, iGPT-XL, contains L = 60 layers and uses an embedding size of d = 3072 for a total of 6.8B parameters.
-- Our next largest model, iGPT-L, is essentially identical to GPT-2 with L = 48 layers, but contains a slightly smaller embedding size of d = 1536 (vs 1600) for a total of 1.4M parameters.
+- Our next largest model, iGPT-L, is essentially identical to GPT-2 with L = 48 layers, but contains a slightly smaller embedding size of d = 1536 (vs 1600) for a total of 1.4B parameters.
 - We use the same model code as GPT-2, except that we initialize weights in the layerdependent fashion as in Sparse Transformer (Child et al., 2019) and zero-initialize all projections producing logits.
 - We also train iGPT-M, a 455M parameter model with L = 36 and d = 1024
 - iGPT-S, a 76M parameter model with L = 24 and d = 512 (okay, and how many heads? looks like the Github code claims 8)