why number 8549176320 is one of a kind?

I am the black child of a white father, a wingless bird, flying even to the clouds of heaven. I give birth to tears of mourning in pupils that meet me, even though there is no cause for grief, and at once on my birth, I am dissolved into air. What am I?

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

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

Find The Missing Number In the Sequence.
6 25 64 ? 32 1

I travel all around the world but always stay in the corner. What am I?

The host of a game show offers the guest a choice of three doors. Behind one is an expensive car, but behind the other two are goats.
After you have chosen one door, he reveals one of the other two doors behind which is a goat (he wouldn't reveal a car).

Now he gives you the chance to switch to the other unrevealed door or stay at your initial choice. You will then get what is behind that door.

You cannot hear the goats from behind the doors, or in any way know which door has the prize.

Should you stay, or switch, or doesn't it matter?

Analyze and find the missing item in the sequence:
16, 06, 68, 88, __, 98

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

What number do you get when you multiply all of the numbers on a telephone's number pad?