1 million seconds is equal to approximately 11.57 days, while 1 billion seconds is equal to approximately 31.71 years.

To convert seconds to days, we divide the number of seconds by the number of seconds in a day. Since there are 86,400 seconds in a day (24 hours x 60 minutes x 60 seconds), we can calculate the number of days as follows:

- 1 million seconds ÷ 86,400 seconds/day = 11.57 days (rounded to two decimal places)
- 1 billion seconds ÷ 86,400 seconds/day = 31,709.79 days (rounded to two decimal places)

Since there are approximately 365.25 days in a year (taking into account leap years), we can convert the number of days to years by dividing the number of days by 365.25:

- 11.57 days ÷ 365.25 days/year = 0.03 years (rounded to two decimal places)
- 31,709.79 days ÷ 365.25 days/year = 86.64 years (rounded to two decimal places)

So, 1 million seconds is equivalent to approximately 0.03 years or 11.57 days, while 1 billion seconds is equivalent to approximately 86.64 years or 31.71 days.