I don't think it's that easy... Usually there is a lot of confusion & translation bugs within vendor chain.
- Speed Variation Ratio 1/64 => gear ratio, output shaft is driven via a 64:1 gear ratio
- Stride Angle 5.625°/64 => motor has a step angle of 5.625°, and the resulting output shaft (gear ratio 1/64) movement will be 0,088°
But the big question: What is a motor step?
Here marketing begins to involve. Usually they specify using halfstep mode (8 halfsteps, 1-2 phase excitation), to make the motor look nicer.
Phys. fullstep resolution is based on fullstep mode (4steps, as you have 4 coils), resulting in 11,25° per fullstep.
The motor has 32 poles (360°/11,25°), so you need 2048 fullsteps, to make a full shaft rotation (32*64)
Dependent on the torque you need, you may go with 1-1 or 2-2 phase excitation (both 4 fullsteps) or 1-2 (8 halfsteps)
All of them have pro&con, so it depends on your application needs & driver capabilities.