IntegerReverse

The integer whose digits are those of $n$ in reverse order.

✓ checked against that system · ! checked, with disagreements (hover a chip)Wolfram LanguageIntegerReverse✓↗

IntegerReverse(n)the base-10 digits of $n$, reversed

IntegerReverse(n, base)reversed in the given base

IntegerReverse(n, base, len)padded to len digits (leading zeros) before reversing

Typed signatures

Type	Package	Applies
(integer, any?, integer?) -> integer	numerals	always

Domain: Numeral systems

Details

• A trailing zero of $n$ becomes a leading zero of the reversal, which then simply vanishes — IntegerReverse(1200) is 21, not 0021
• The sign of $n$ is not carried through; the digits reverse as if $n$ were non-negative

Examples

Basic #

the base-10 digits reversed

live ↗

In$\mathrm{IntegerReverse}(1\,234)$Out$4\,321$

Reverses the decimal digits

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In$\mathrm{IntegerReverse}(123\,456)$Out$654\,321$

A binary palindrome: $2015=11111011111_2$

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In$\mathrm{IntegerReverse}(2\,015, 2)$Out$2\,015$

A length argument pads with leading zeros first, so reversal gains trailing zeros

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In$\mathrm{IntegerReverse}(1\,234, 10, 6)$Out$432\,100$

Scope #

$1234 = 10011010010_2$ reversed is $1001011001_2 = 601$

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In$\mathrm{IntegerReverse}(1\,234, 2)$Out$601$

padded to 5 digits first: $00123$ reversed

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In$\mathrm{IntegerReverse}(123, 10, 5)$Out$32\,100$

Listable

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In$\mathrm{IntegerReverse}(\bigl\lbrack12, 345\bigr\rbrack)$Out$\bigl\lbrack21, 543\bigr\rbrack$

Threads over a list

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In$\mathrm{IntegerReverse}(\bigl\lbrack123, 234, 345, 456\bigr\rbrack)$Out$\bigl\lbrack321, 432, 543, 654\bigr\rbrack$

live ↗

In$\mathrm{IntegerReverse}(1\,234, \mathrm{MixedRadixNumerals}(\bigl\lbrack7, 11\bigr\rbrack))$Out$170$

Applications #

a palindrome is its own reversal

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In$\mathrm{IntegerReverse}(12\,321)$Out$12\,321$

Properties #

The digits of 842 read backwards

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In$\mathrm{IntegerReverse}(842)$Out$248$

Trailing zeros vanish when reversed

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In$\mathrm{IntegerReverse}(84\,200)$Out$248$

Possible issues #

trailing zeros become leading zeros and vanish

live ↗

In$\mathrm{IntegerReverse}(1\,200)$Out$21$

About

Examples	13
Checked against	Wolfram Language 13 agree
Crosswalk	Wolfram Language

See also: IntegerDigits, IntegerLength