Convert-Int64ToText.ps1

function Convert-Int64ToText {
    <#
.SYNOPSIS
    Convert integer to English text
.DESCRIPTION
    Convert integer to English text
.PARAMETER Number
    An [int64] value or an array of [int64]
.PARAMETER IncludeInput
    Switch to enable the original datetime to appear in the output. Aliased to 'IncludeOriginal'
.EXAMPLE
    Convert-Int64ToText -Number 13987

    Thirteen Thousand Nine Hundred Eighty Seven
.EXAMPLE
    Convert-Int64ToText -Number 1999, 2001, 2022 -IncludeInput

    Number Result
    ------ ------
      1999 One Thousand Nine Hundred Ninety Nine
      2001 Two Thousand One
      2022 Two Thousand Twenty Two
.EXAMPLE
    723, 4560 | Convert-Int64ToText -IncludeInput

    Number Result
    ------ ------
       723 Seven Hundred Twenty Three
      4560 Four Thousand Five Hundred Sixty
#>

    [cmdletbinding()]
    [alias('Convert-IntToText')] #FunctionAlias
    param (
        [Parameter(Mandatory, ValueFromPipeline, Position = 0)]
        [int64[]] $Number,

        [switch] $IncludeInput
    )

    begin {
        Write-Verbose -Message "Starting [$($MyInvocation.Mycommand)]"
        Write-Verbose -Message "Number [$Number] IncludeInput [$IncludeInput]"
        if (($Number -lt -999999999999) -or ($Number -gt 999999999999)) {
            Write-Error -Message '-Number too large or too small. The absolute value of the number must be less than or equal to 999,999,999,999'
            break
        }
        $class = @'
public class PFNum2Word
    {
    public static string NumberToText( long n)
        {
        if ( n < 0 )
            return "Minus " + NumberToText(-n);
            else if ( n == 0 )
            return "";
        else if ( n <= 19 )
            return new string[] {"One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight",
            "Nine", "Ten", "Eleven", "Twelve", "Thirteen", "Fourteen", "Fifteen", "Sixteen",
            "Seventeen", "Eighteen", "Nineteen"}[n-1] + " ";
        else if ( n <= 99 )
            return new string[] {"Twenty", "Thirty", "Forty", "Fifty", "Sixty", "Seventy",
            "Eighty", "Ninety"}[n / 10 - 2] + " " + NumberToText(n % 10);
        else if ( n <= 199 )
            return "One Hundred " + NumberToText(n % 100);
        else if ( n <= 999 )
            return NumberToText(n / 100) + "Hundred " + NumberToText(n % 100);
        else if ( n <= 1999 )
            return "One Thousand " + NumberToText(n % 1000);
        else if ( n <= 999999 )
            return NumberToText(n / 1000) + "Thousand " + NumberToText(n % 1000);
        else if ( n <= 1999999 )
            return "One Million " + NumberToText(n % 1000000);
        else if ( n <= 999999999)
            return NumberToText(n / 1000000) + "Million " + NumberToText(n % 1000000);
        else if ( n <= 1999999999 )
            return "One Billion " + NumberToText(n % 1000000000);
        else if ( n <= 999999999999 )
            return NumberToText(n / 1000000000) + "Billion " + NumberToText(n % 1000000000);
        else
            return "";
    }
}
'@

        Add-Type -TypeDefinition $class
    }

    process {
        foreach ($curNumber in $Number) {
            $Result = ([PFNum2Word]::NumberToText($curNumber))
            $Result = $Result.Trim()
            if ($IncludeInput) {
                New-Object -TypeName pscustomobject -Property ([ordered] @{
                        Number = $curNumber
                        Result = $Result
                    })
            } else {
                Write-Output -InputObject $Result
            }
        }
    }

    end {
        Write-Verbose -Message "Ending [$($MyInvocation.Mycommand)]"
    }
} # EndFunction Convert-Int64ToText