There is no definite answer to this question because the world's greatest novel is a subjective question. Different people may have different answers. Some people might think that Harry Potter and the Sorcerer's Stone is the greatest novel in the world because it creates a world full of magic and fantasy and tells the story of a group of students who realize their dreams through the Sorcerer's Stone. Others might think that Pride and Predict is the greatest novel in the world because it portrays the life of the British upper class, tells the story of the feud between the two families, and reveals the complexity and emotions of human nature. Some people may think that Dream of the Red Chamber is the greatest novel in the world because it portrays the life of the feudal society in the Qing Dynasty, reveals the complexity and emotions of human nature, and shows the complexity and richness of Chinese culture. The world's greatest novel is a subjective question. Everyone's answer may be different.