I have recently bought a second-hand iMac (21.5-inch, late 2013; 2.7 GHz Quad-Core Intel Core i5) - Catalina is installed but there does not seem to be an upgrade path to Mojave. Does this mean my Mac cannot handle 64-bit software?
iMac 21.5″, macOS 10.15
Your machine can't run anything before Mountain Lion, which would have supported running 64-bit applications on compatible CPUs.
MacTracker says your CPU is a 4-core Intel Core i5 (4570R) with 64-bit architecture.
That doesn't mean your computer can actually take 2^64 bytes (16 billion gigabytes) of RAM. The limit on that CPU is 32 GB and on your iMac is 16 GB. The 64-bit support does make it possible to go past 2^32 bytes (4 gigabytes).
Catalina is 64bit only. Mojave would be a downgrade from Catalina.
one would have to downgrade to mojave to run 32bit apps really
10.5 Leopard x86 x86/x64 from 2007
was the first macOS that enabled users to run 64bit apps
My iMac won't run 64 bit applications
