Other compelling reasons why you might want to create 64-bit applications are as follows:
You can perform a lot of computation on 64-bit integer values that use the wide data paths of a 64-bit processor to gain performance.
Several system interfaces have been enhanced, or limitations removed, because the underlying data types that underpin those interfaces have become larger. For example, 32-bit time_t can only handle dates up to January 2038, while 64-bit time_t can handle dates for billion years into the future.
You can obtain the performance benefits of the 64-bit instruction set, such as improved calling conventions and full use of the register set.
You can increase the security by using ASLR, which helps you to create more random, harder to guess address spaces.