There is an old (IIRC non-standard) convention from the classful IP times which allows you to write not only X.Y.Z.W but also X.Y.ZW, X.YZW, and occasionally even XYZW with ZW = 256 × Z + W (decimal) etc., all referring to the same host. So 1.0.1, 1.1, and 16777217 are all funny ways to write 1.0.0.1, which is indeed an alternative address for Cloudflare’s 1.1.1.1—also written 1.1.257, 1.65793, and 16843009.