What is the next number in this matchsticks series riddle?

John was visiting his friend Jacob. He found out that his friend's wife had just killed a burglar in self-defense.
John asks Jacob about what happened and he told that "His wife was watching television when suddenly the bell rang. She thought that it is her husband Jacob but she found the burglar who attacked her instantly and she got so frightened that she killed the burglar immediately with the knife.
John asked the police to arrest his friend's wife. Why?

If nine thousand, nine hundred nine dollars is written as $9,909,
how should twelve thousand, twelve hundred twelve dollars be written?

There is something which you can be arrested for attempting but not for successfully completing.

I am under you when I am whole.
I shift above you if you remove the first letter.
I come all around you if you remove the second as well.

Can you tell me who I am?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

Solve below rebus puzzle?

Find the next number in the sequence

1, 2, 6, 21, 88, __?

Buy me, smell me or deliver me, I do not change.

Who am I?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?