It is all explained here:
http://support.sas.com/documentation/cdl/en/lrcon/62955/HTML/default/viewer.htm#a000695157.htm
and
http://www.sascommunity.org/wiki/Numeric_representation_issues_in_SAS
The larger integer sas can accurately represent with 8 bytes is 9,007,199,254,740,990 under Windows and 72,057,594,037,927,900 on mainframes.
Your number 12,345,678,912,345,445 is too large for the Windows platform.
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