# IEEE largest number for any machine representation

If we consider a machine that uses 64 bits to represent a number.

If 1 bit is used for sign, "x" bits to represent mantissa and (63-x) to store the (biased) exponent in a manner similar to the IEEE representation.

I'm using this question to check my knowledge of IEEE. Can we say the largest positive number using this machine is: $\left ( 63-x \right )* 2^{2^{x}-1}$

• You've got a few things wrong in your formula. – gnasher729 Jan 20 '18 at 20:21
• The largest positive IEEE number is +Infinite ;-) – TEMLIB Jan 20 '18 at 20:36
• According to your formula, the usual double precision numbers can store numbers up to a million billion digits. In reality, it's only about 300 digits. – gnasher729 Jan 21 '18 at 19:59