Think of this as a slightly different question, and the answer becomes more clear.
How many times do you have to circle the Sun to leave orbit?
The Earth has been orbiting our Sun for about 4.5 Billion years with each year being one orbit. The Earth is expected to stay in orbit around the Sun for the next few billion years.
Also consider the moon has been orbiting the Earth for about the same 4.5 billion years. ~12 orbits a year for 4.5 billion is ~54 billion orbits and it is still there.
The number of orbits is not relevant to leaving orbit.