Since there are 86,400 seconds in a day and 365.25 days in a year, a 9-year old has lived at least 284,018,400 seconds.
25 years is 788,923,150 seconds.
The answer depends on your 13 year old what! And what has your 13 year old possession got to do with your age, anyway?
you have lived 409968000 seconds in 13 years 409968000 seconds
A 9 year old will have lived through at least 2 leap years, so allowing for that, they will have been alive for 283,996,800 seconds. It is possible they have lived through 3 leap years in which case they will have been alive for 284,083,200 seconds.
47 years = 1,482,192,000 seconds
72 years is about 2,272,098,672 seconds.
12 years is 378,683,112 seconds.
34.2 years is about 1,079,246,869.2 seconds.
17 years is 536,467,742 seconds.
1 year is approximately 31.56 million seconds, so 60 billion seconds is a little over 1901 years.