You can enter numbers in different formats, according to your needs and preferences. Hypatia processes and stores them independent of the format in which you have entered them.
Integer: You can enter integer numbers with up to 18 digits.
Floating point: You can enter floating point numbers (numbers with a decimal point in them) with as many digits as you want, but more than 16 or 17 significant digits will be redundant. Hypatia shows numbers with up to 15 significant digits.
A leading zero before the decimal point can be omitted.
Scientific notation: The exponent must be an integer in the range of plus/minus 1000.
Because there is no hard limit to the significand (the number before the E) you can enter numbers larger than 1E1000, but no results (including intermediate results) can be larger than 1E1000. Numbers smaller than 1E-1000 are zero.
Millions: You can add the word MILLION after a number, to multiply it with one million.
Lakh, Crore: You can add the words LAKH or CRORE after a number, to multiply it with one hundred thousand or ten million.
Hexadecimal: With the prefix &H you can enter hexadecimal numbers.
Binary: With the prefix &B you can enter binary numbers.
Negative numbers: You can put a minus sign in front of a number in any format.
You can structure numbers with many digits (also hexadecimal or binary numbers) by inserting apostrophes between the digits. Hypatia simply ignores them.