Mathematica provides flexible mechanisms for full typeset formatting of numbers of any magnitude and precision, to optimize readability, portability and external compatibility.
NumberForm — general control of number display
PaddedForm — insert padding to align numbers
InputForm,
OutputForm — plain text versions of numbers
CForm,
FortranForm — C and Fortran-like "E" notation
NumberMarks — option to include precision information with
` marks
$NumberMarks — globally determine whether to use
` marks for number portability
N — compute to specified precision