Approximately 22 lakh and 51 thousand square miles area was brought under the Muslim control during the reign of?

Approximately 22 lakh and 51 thousand square miles area was brought under the Muslim control during the reign of?

تقریباً 22 لاکھ 51 ہزار مربع میل کا علاقہ کس کے دور حکومت میں مسلمانوں کے زیر تسلط آیا؟
Explanation

Approximately 22 lakh and 51 thousand square miles area was brought under Muslim control during the reign of Hazrat Umar (R.A).