2N-COUNT 独通一行的人;独开一窍的人;天才型弱智者 You can refer to someone as an idiot savant if they seem to be less intelligent than normal people but are unusually good at doing one particular thing. 独通一行的人;独开一窍的人;天才型弱智者
...an idiot savant, an autistic with a gift for numbers.