What is the great reward-yielding Dhikr for someone who cannot read the Qur'an but wishes to compete for reward? And is there a reward for memorizing the Qur'an by listening to an audio recording?

A Muslim should bear two important things in mind: First, that the Qur'an is made easy for remembrance and study, as Allah the Almighty says: "And We have certainly made the Qur'an easy for remembrance, so is there any who will remember?" Second, that whoever finds its learning and memorization difficult will have a double reward, as stated in the Hadith: "The one who is proficient in the Qur'an will be with the noble and righteous scribes (angels), and the one who recites the Qur'an and stutters over it, and it is difficult for him, will have two rewards."

Among what aids in memorizing the Qur'an is frequently listening to it via a recorder. This achieves the intended purpose for those who do not have access to a direct teacher. It is preferable to combine direct memorization with listening for revision and ensuring accuracy.

The door of competition in good deeds is open to everyone. Whoever cannot compete in (memorizing) the Qur'an, let him compete in prayer, or fasting, or charity, or remembrance (dhikr), or enjoining good and forbidding evil, or maintaining kinship ties, or showing dutifulness to parents. Among the remembrances with great reward are: reciting "Qul Huwa Allahu Ahad" (Say: He is Allah, [the] One), which is equivalent to one-third of the Qur'an; Surat Al-Fatihah, which is the best surah in the Qur'an; Ayatul Kursi, which is the greatest verse; the last two verses of Surat Al-Baqarah; saying: "Subhanallahi wa bihamdihi, adada khalqihi, wa rida nafsihi, wa zinata arshihi, wa midada kalimatihi" (Glory be to Allah and His praise, as many times as the number of His creations, as much as pleases Him, as much as the weight of His Throne, and as much as the ink of His words); and saying: "Subhanallahi wa bihamdihi, Subhanallahil-Azim" (Glory be to Allah and His praise, Glory be to Allah, the Most Great); and Sayyidul Istighfar (the master supplication for forgiveness); and morning and evening remembrances; and remembrances after prayers; and sleep remembrances.

It is prescribed for a Muslim to diversify in acts of worship and not to confine oneself to one type, because that would cause him to miss out on the reward of other virtues and might lead to boredom and weariness.