কুরআনের সর্বমোট রূকুর সংখ্যা কত ?
Rukūʿ () refers to two things in Islam. 
1. RUKU is a step of prayer in Islam where someone bows down (places hands on knees) and then goes to Sajdah (placing forehead on the ground). 
2.A paragraph of the holy book Qur'an. 
There are 558 "rukūʿs" in the Qur'an. In some books, 540 have been mentioned which is actually misunderstood by some people with total rukus of quran recited in Salat-ut-Taraweeh (special prayer in the Islamic month of Ramadan after the night prayer). This subdivision is not part of original revelation but adopted later-on to facilitate completion of Quran on the 27th night of Ramadhan (i.e. on Laylatul Qadr) if one ruku is recited in each rakat of taraweeh prayers (20 x 27 = 540). 
558