28222149
This number is a composite.
28222149 is a semiprime S = A * B (with A = 3 and B = 9407383) such that A.B , B.A , S.A , S.B , A.S , S.A.B , S.B.A , A.S.B , A.B.S , B.S.A , B.A.S are all semiprime (dots here mean concatenation). [Tolgede]
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