What do you mean? It should be easy enough to remember that it is 2^32.
If you want a rule to memorize the value of that number, a handy rule of thumb is for converting between binary and decimal in general:
2^10 ~ 1000
which means 2^20 ~ 1,000,000
and 2^30 ~ 1,000,000,000
Double that (2^31) is rounghly 2 billion, and doubling that again (2^32) is 4 billion.
It's an easy way to get a rough estimate of any binary number. 10 zeroes in binary becomes 3 zeroes in decimal.
