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

On my way to St. Ives I saw a man with 7 wives. Each wife had 7 sacks. Each sack had 7 cats. Each cat had 7 kittens. Kittens, cats, sacks, wives. How many were going to St. Ives?

Three cars are driving on a track that forms a perfect circle and is wide enough that multiple cars can pass anytime. The car that is leading in the race right now is driving at 55 MPH and the car that is trailing at the last is going at 45 MPH. The car that is in the middle is somewhere between these two speeds.
Right now, you can assume that there is a distance of x miles between the leading car and the middle car and x miles between the middle car and the last car and also, x is not equal to 0 or 1.
The cars maintain their speed till the leading car catches up with the last car and then every car stops. In this scenario, do you think of any point when the distance between any two pairs will again be x miles i.e. the pairs will be x distance apart at the same time ?

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

Find the smallest sentence with all the English alphabet.

Paul's height is six feet, he's an assistant at a butcher's shop and wears size 9 shoes. What does he weigh?

Can you make numbers like 24, using numbers 3,3,7 & 7 with any arithmetic operator?

What is in seasons, seconds, centuries and minutes but not in decades, years or days?

Find The Next Number in the series:

12 13 15 17 111 113 117 119 123 ?

Here is a mathematical expression that also secretly tells a movie name. What movie is that?