Why is Excel truncating my 16-digit numbers? [duplicate]

If I type in a 16 digit number (format: number, no decimals) it changes the number on me. Example: 1234567812345678 changes the view to 1234567812345670.

If I type it in as a general format it changes the numbers above so it displays 1.23457E+15 but if you click on the cell, the display shows the last digit as a 0 instead of an 8 once again.

I opened the file on a different computer and same issue now with it. I have changed the auto correction and auto formatting all to no avail. Help!

It is a limitation placed on Excel by Microsoft. Each cell can have a maximum 15 digits of precision.

http://office.microsoft.com/en-us/excel-help/excel-specifications-and-limits-HP005199291.aspx

In addition to wbeard52's answer, here are some workarounds:

1. Entering the numbers as text. You may type a ' before each number, or change the cell's number format to Text.
2. There's an addin called Xnumbers which "performs multi-precision floating point arithmetic from 1 up to 250 significant digits."