Note that intrinsic can be defined as "belonging to a thing by its very nature".
The intrinsic functions were added to the COBOL 85 standard via an amendment in 1989 (almost 20 years ago!) and are supported across all platforms that conform to the standard as amended. I've used these on various IBM mainframes, AcuCOBOL (which supports almost any OS known to man), and the HP-3000. Even the open source TinyCOBOL supports them.
They are a widely recognized part of standard COBOL.
Regards,
Glenn