Can you find the odd number in the following?

2716, 4135, 5321 and 7145

As easy as you can get into me, it is as hard to get out of me.

Do you know what I am?

Can you place six X (crosses) in below board without making three in a row in any way ?

In one of the popular batman series movie "Batman Forever", there was a riddle that goes like "Tear me off and then scratch my head and I was red then and now I am back. Who am I?

What brings you down but never up?

Solve the mathematical equation in the picture below.

I am an eight letter word and I am a computer terminology.
The second, third and fourth letters make an animal.
The fourth, fifth, sixth, seventh and eighth letters make a weapon.
The first, second, third and fourth letters can be taken as an outcome of any exam.
The fifth, sixth, seventh and eighth letter combine to form a high end typing software.

Can you tell who am I ?

How can one talk without saying a single word?

What does this rebus riddle means ?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?