They are called Quintillion Annealer(s) because they "can" support upto a Quintillion Fully Connected Error Free Qubits, that's 10^18 Qubits
While they natively solve Ising Problems (QUSO & PUSO) they also solve QAOA, QUBO, PUBO etc.
Supports upto 1 Quintillion Fully Connected Error Free Qubits