Is $7 million enough to retire at 60?

Could you please elaborate on whether seven million dollars is considered sufficient for retirement at age 60? I'm curious about the factors that might influence this decision, such as living expenses, inflation rates, and investment returns. Additionally, would it be advisable to consider other financial vehicles or strategies to ensure a comfortable and secure retirement? Given the uncertainties in the financial world, how can we ensure that this amount will last throughout our retirement years? Thank you for your insights.