The bcmod function is deactivated and I won't be able to activate this because its not my own server.

For a reason I need to calculate an integer with a length of atleast 24 with modulo 97. Integer cant be that long, thats why it can't work...

I already tried it with simple operator "%" and the "fcmod" lib but this returns me completely wrong numbers.

Does someone know if I can solve this by my own without any other libraries or do I really need "bcmod"?

This would be the code as example:

123456789101112131415171