  The largest number factored on a quantum device reported until now was 143.
That quantum computation, which used only 4 qubits at 300K, actually also
factored much larger numbers such as 3599, 11663, and 56153, without the
awareness of the authors of that work. Furthermore, unlike the implementations
of Shor's algorithm performed thus far, these 4-qubit factorizations do not
need to use prior knowledge of the answer. However, because they only use 4
qubits, these factorizations can also be performed trivially on classical
computers. We discover a class of numbers for which the power of quantum
information actually comes into play. We then demonstrate a 3-qubit
factorization of 175, which would be the first quantum factorization of a
triprime.
