How old was Victor Frankenstein when he died?

In Mary Shelley's Frankenstein, many characters die, including the main character, Victor Frankenstein. In fact, Victor is the last one to die. Some might call this poetic justice, since he was the cause of so much grief and death to begin with. Victor is the "mad scientist" of the story, the one who creates the monster that comes back to haunt him. 
In the book, Victor is obsessed with cheating death. His mother has died of scarlet fever, and he wants to not have to experience death. He soon learns that is a terrible idea, however, as the corpse parts he pieces together spark into life and wreak havoc, not knowing how to master human emotions. After the murder of his brother, Victor goes to find the monster, who tells him that he just wants a companion.  Victor takes pity on him and makes one but second-guesses this decision. He ends up killing the she-monster. Later, he goes to jail for the murder Clerval for which he is framed. When he gets out, he is all set to go back and marry his adoptive sister and love of his life, Elizabeth, but discovers that she has also been murdered by the monster.
Finally, Frankenstein Sr. dies, depressed after the death of his daughter. Victor vows to pursue the monster to the ends of the earth. He tracks him to the Arctic Ocean, where he boards a ship run by Captain Walton. The ship is stuck in the ice. Victor tells him his entire story and, filled with regret and sadness, dies on the ship. His exact age at the time of death is unknown, as Mary Shelley intentionally left the dates of his life vague. There is, however, speculation that a certain German scientist named Johann Dippel is the man off of whom the character of Frankenstein was based. He died in 1734 at the age of 61.