Is $1M enough for a person to retire for 20 years?

Is $1M enough for a person to retire for 20 years (assuming the person retire at 62 years old and live till 82 years old)? 

Recently, there are many people who are starting to complain that cost of living in Singapore has gone too high, and $1M is not even enough for a person to retire!  Is this a fact or a myth (just belief and misconception)? 

To be realistic, we have to take the cost of living of basic necessities, no frails - because cost of living for frails and luxuries are not necessities and are just WANTs, not NEEDs... 

Ok, why not we put a hard figure to it once and for all to prove or disprove it?  Here we go!...

Costs of living per month per person (average figure):

- Food = $330 (cook at home, with occasional eat out)
- Transport = $150 (bus and trains only, should be much less for retirees)
- Utilities (electricity, water, gas, sewage) = $120
- Communications (mobile phones subscriptions & internet) = $80
- Clothings and footwear = $100
- Medical insurance & expenses = $200 (assume the rest covered by insurance)

Total per month = $980 per month per person. 

Let's assume inflation of cost of living is 2% per year.
Let's assume this person put his $1M into annuity earning 2% per year at the age of 62 years old.

At the end of 82 years old, he would still have about S$1,153,000 !!
So, $1M is more than enough for a person to retire!!