If a cryptographic hash function uses 32 bit digest, How many digests needs to be created to find original message with probability of 0.5 or better?

(The format of the answer should be in decimal and rounded. Neglect the digits after the decimal point. For example, 12345.)

Given system can create 0.69 X 2^20 messages digest per second. What is time needed to find this in terms of hours.

(The format of the answer should be in decimal and rounded. Neglect the digits after the decimal point. For example, 12345.)