How does Banquo's reaction to the prophecy differ from Macbeth's? What does this say about his character?

Macbeth and Banquo's friendship suggests that their reactions to the prophecies of the witches might be identical, or, at the very least, similar. However, it is through their differing reactions to the prophecies that readers can see some very fundamental differences in the individual personalities/characters of Macbeth and Banquo. 

When Macbeth and Banquo encounter the witches in Act 1, Scene 3, they are both curious about the witches. Banquo actually addresses the witches first: "Live you? or are you aught / That man may question?" He appears curious about them, but more from a disbelieving perspective than one of seeking information from supernatural beings. 

A few moments later, however, after the witches have greeted Macbeth with the three prophecies that will guide the course of the play, Banquo becomes far more interested in their seeing abilities. He, unlike Macbeth, actually asks the witches to tell his future. He says, "If you can look into the seeds of time, / And say which grain will grow and which will not, / Speak then to me, who neither beg nor fear / Your favors nor your hate" (Act 1: Scene 3).

This different reaction from Macbeth could suggest to readers that Banquo is, perhaps, the more susceptible character to the witches' influence. (And, had Lady Macbeth not stepped in and motivated Macbeth into action, perhaps it would have been a different play entirely!) His attention to the witches and their prophecies suggests that he is the type of person who, while he may not want to cheat fate, doesn't mind having some extra information to help guide his choices. He appreciates guidance; we see this in his relationship with Macbeth as well. 

Ultimately, Banquo disregards the prophecies of the witches as an amusement or as the musings of crazy people. This is understandable, considering that, though Macbeth's prophecies were specific and direct (Thane of Cawdor, "thou shalt be king hereafter!"), the prophecies to Banquo were stated as riddles: "Lesser than Macbeth, and greater... Not so happy, yet much happier..." and as the seemingly impossible: "Thou shalt get kings though thou be none..." (Act 1: Scene 3).

Overall, we can see that, based on his character, Banquo had an inclination to be far more swayed by the witches than Macbeth; perhaps Banquo was even the original target of their spell-casting, but, because of Macbeth's aggressive ambition and Banquo's tendency to be more of a follower than a leader, he placed less importance on the prophecies than Macbeth ultimately did.