# Wolfram Language & System 10.3 (2015)|Legacy Documentation

This is documentation for an earlier version of the Wolfram Language.
WOLFRAM LANGUAGE GUIDE

# Number Digits

The Wolfram Language can handle numbers of essentially unlimited length, in any base, using state-of-the-art platform-optimized algorithms, including several developed at Wolfram Research. For rational numbers, it uses number theoretic methods to efficiently find the exact forms of repeating digit sequences.

## ReferenceReference

IntegerDigits digits of an integer

RealDigits digits of a real number

FromDigits reconstruct a number from its digits

IntegerLength total number of digits in an integer

DigitCount count the number of occurrences of given digits

IntegerReverse integer obtained by reversing digits

IntegerString digits of an integer as a string

BaseForm display a number in base b

IntegerName name of an integer (e.g. "thirty-five")

NumberDecompose decompose into multiples of units (e.g. currency denominations)

NumberCompose reconstruct a number from its decomposition