I recently made a cheque printing application for a business I was working with and I had to convert a number into it's written form. I did some searching and found some stuff, but I didn't like how they were implemented or written. Not to mention the spelling mistakes. Anyway, the attached class can internally handle up to 63 digits which is a hundred Vigintillion, anything past 63 digits requires a delegate where you supply the name of the larger number.
Dim value = "109284021804812094102984012804812048102840912840812048127250412785"
If you want more than 63 digits:
One Hundred Nine Vigintillion Two Hundred Eighty Four Novemdecillion
Twenty One Octodecillion Eight Hundred Four Septendecillion Eight Hundred
Twelve Sexdecillion Ninety Four Quindecillion One Hundred Two
Quattuordecillion Nine Hundred Eighty Four Tredecillion Twelve Duodecillion
Eight Hundred Four Undecillion Eight Hundred Twelve Decillion Forty Eight
Nonillion One Hundred Two Octillion Eight Hundred Forty Septillion Nine
Hundred Twelve Sextillion Eight Hundred Forty Quintillion Eight Hundred
Twelve Quadrillion Forty Eight Trillion One Hundred Twenty Seven Billion Two
Hundred Fifty Million Four Hundred Twelve Thousand Seven Hundred Eighty Five
Dim value = "1092840218048120941029840128048120481028409128408120481272504127851244654511"
Console.WriteLine(NumberConverter.Convert(value, AddressOf Me.OnQueryLargeNumberText))
Private Function OnQueryLargeNumberText(index As Integer) As String
Select Case index * 3
Return "Huge Tons"
Return "Crap Tons"
Return "Way Too Muchs"
Return "I Give Up's"
One I Give Up's Ninety Two Way Too Muchs Eight Hundred Forty Crap Tons
Two Hundred Eighteen Huge Tons Forty Eight Vigintillion One Hundred
Twenty Novemdecillion Nine Hundred Forty One Octodecillion Twenty Nine
Septendecillion Eight Hundred Forty Sexdecillion One Hundred Twenty Eight
Quindecillion Forty Eight Quattuordecillion One Hundred Twenty Tredecillion
Four Hundred Eighty One Duodecillion Twenty Eight Undecillion Four Hundred
Nine Decillion One Hundred Twenty Eight Nonillion Four Hundred Eight Octillion
One Hundred Twenty Septillion Four Hundred Eighty One Sextillion Two
Hundred Seventy Two Quintillion Five Hundred Four Quadrillion One Hundred
Twenty Seven Trillion Eight Hundred Fifty One Billion Two Hundred Forty Four
Million Six Hundred Fifty Four Thousand Five Hundred Eleven