There are 60 seconds in a minute, 60 minutes in an hour, 24 hours in a day, 365 days in a year, for 2012 years. Multiply all those numbers to convert from 2012 years to seconds and you get 63,450,432,000 seconds.
There were 13880 days, including 10 days in leap years from 1975 to 2012. That makes 1,199,232,000 seconds. However, during this period there were 21 leap seconds, so the correct answer is 1,199,232,021 seconds.
2590200 seconds
There are about 31,557,000 seconds in a year. Since 2012 is three years from now, that is 94 million, 673 thousand seconds. There are about 2.6 million seconds in a month, and since January 2009 is now almost over, 94.6 - 2.6 = 92 million seconds until New Year's Day, 2012. I wouldn't waste time counting them one by one...
There are 1263141040 seconds in 40 years
10 years = 315,569,260 seconds.
18 years is about 568,036,800 seconds.
About 1,009,843,200 seconds in 32 years.
20 years = 631,138,519 seconds.
25 years = 788,923,149 seconds.
10 years = 315,569,260 seconds.
70 years is about 2,209,032,000 seconds.
800,000,000,000 seconds = 25,351.0117 years.