No. Because even if 15,328,497,237,812 prayers were being uttered in the same second, 15,328,497,237,812 is still a finite number.
However, what is clear is that “hearing” very many prayers at once would require an intellect that is not bound in the same way as the human intellect is on earth.
One way in which it is obviously different is that—outside of the Blessed Virgin Mary, who already has a glorified, heavenly body—the intellects of the Saints do not understand through the medium of matter. They grasp things in a manner that is purely spiritual.
How that functions is unknown to us. But I have to point out that the fact that we cannot provide a complete psychological analysis of a spirit in heaven is by no means relevant here. We can see that there is nothing logically contradictory in the idea of a glorified intellect grasping vast sums of data much differently from how an earthly intellect does.
Moreover, asking the question is a bit like asking how a Saint can hear prayers when they don’t have ears and since, besides, they are apparently out of earshot of the person praying. And what about silent prayers? How could you hear something that has no sound waves?
Don’t you need to BE God for such things? No. You just NEED God for such things.
God has the ability to infuse into my intellect absolutely whatever He wants. If He so chose, I could be fluent in every human language ever uttered in a mere 2.34 seconds.
The fact that I couldn’t do that on my own doesn’t affect whether or not I could do that with His help.
But ultimately, this question will go back to the question of sola Scriptura: if Saintly intercession is not Biblically taught to the subjective satisfaction of the Protestant, then they will be more likely to reject it.
So all of these question need to address sola Scriptura, too. We can find evidence in the Bible of how the glorified body is different from the earthly one, or how God uses intercession to give gifts of grace to certain persons, or how it appears that the prayers of the Saints in heaven rise before God’s throne like incense.
But if sola Scriptura is not examined, we will not be presenting the totality of the Catholic understanding of all of this.