With 1M, voltages of up to 13.2V can be read. Voltages over 13.2V will also read 13.2V, because the voltage at the esp pin will be more than 1.0V.
To avoid damage to the esp pin, the voltage at the pin on the esp chip itself must not exceed 3.3V. This corresponds to an input voltage to your circuit of 3.3 / 100K * (1M + 220K) = 40.26V
Someone please correct me if I am wrong about this!