What do numbers using 0x notation mean?

Question

Literals that start with 0x are hexadecimal integers. (base 16)

The number 0x6400 is 25600.

6 * 16^3 + 4 * 16^2 = 25600

For an example including letters (also used in hexadecimal notation where A = 10, B = 11 ... F = 15)

The number 0x6BF0 is 27632.

6 * 16^3 + 11 * 16^2 + 15 * 16^1 = 27632
24576    + 2816      + 240       = 27632

In C and languages based on the C syntax, the prefix 0x means hexadecimal (base 16).

Thus, 0x400 = 4×(16²) + 0×(16¹) + 0×(16⁰) = 4×((2⁴)²) = 2² × 2⁸ = 2¹⁰ = 1024, or one binary K.

And so 0x6400 = 0x4000 + 0x2400 = 0x19×0x400 = 25K

It's a hexadecimal number.

0x6400 translates to 4*16^2 + 6*16^3 = 25600

The numbers starting with 0x are hexadecimal (base 16).0x6400 represents 25600.

To convert,

• multiply the last digit times 1
• add second-last digit times 16 (16^1)
• add third-last digit times 256 (16^2)
• add fourth-last digit times 4096 (16^3)
• ...and so on

The factors 1, 16, 256, etc. are the increasing powers of 16.

0x6400 = (0*1) + (0*16^1) + (4*16^2) + (6*16^3) = 25600 

or

0x6400 = (0*1) + (0*16) + (4*256) + (6*4096) = 25600