Simple riddles

I am an odd number; take away a letter and I become even. What number am I?

Create a number using only the digits 4,4,3,3,2,2,1 and 1. So I can only be eight digits. You have to make sure the ones are separated by one digit, the twos are separated by two digits the threes are separated with three digits and the fours are separated by four digits.

What goes up and down the stairs without moving?

I sometimes come in a can but I'm not food. I sometimes come in a bottle but I'm not a beverage. I come in different colors but I'm not a rainbow. I'm sometimes used with canvas but I'm not a tent. I'm used with a brush but I'm not toothpaste. What Am I?

I get whiter the dirtier I get. What am I?

Alive as you but without breath, As cold in my life as in my death; Never a thirst though I always drink, Dressed in a mail but never a clink.

Throw away the outside and cook the inside, then eat the outside and throw away the inside. What is it?

Five add six is eleven, but six add seven is one. How is that possible?

What runs around the house, but does not move?

Suppose you want to send in the mail a valuable object to a friend. You have a box which is big enough to hold the object. The box has a locking ring which is large enough to have a lock attached and you have several locks with keys. However, your friend does not have the key to any lock that you have. You cannot send the key in an unlocked box since it may be stolen or copied. How do you send the valuable object, locked, to your friend - so it may be opened by your friend?