Can you find out which number multiplied by itself will give the output as 12345678987654321?

I have a mouth but I don't eat.
I have a bank but have no money.
I have a bed but i dont sleep.
I wave but have no hands.

Who Am I ?

Which part of London exists in France as well ?

I am not alive, but I grow; I don't have lungs, but I need air; I don't have a mouth, but water kills me. What am I?

Why blonde cannot dial 911?

I cannot talk, but I always reply when spoken to. What am I?

Can you find the thief by just looking at the picture below?

How is a fly different from a mosquito?

There is a jar in which there are two types of candies.
20 blueberries and 16 strawberries. You perform the following steps:
1) You take out two candies.
2) If the two candies are of the same flavour, you add a blueberry one otherwise, you add the strawberry one.

You repeat these two steps till there is just one candy remaining in the jar. Which flavoured candy will be left?

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?