When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

How many sides does a circle have?

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.

If,

A = 1

B = 2

C = 3

...

...

Z = 26.

Based on above rule, you need to find an eleven letter word whose letter sum is equal to 52.

How many times can you subtract the number 5 from 25?

I am beautiful, up in the sky. I am magical, yet I cannot fly. To people I bring luck, and to some people, riches. The boy at my end does whatever he wishes. What am I?

What is more useful when it is broken?

The more you take me, the more you leave me behind.
Who Am I?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

Before Mount Everest was discovered, what was the highest mountain in the world?