The CAS Registry Mumber 17167-19-0 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,7,1,6 and 7 respectively; the second part has 2 digits, 1 and 9 respectively. Calculate Digit Verification of CAS Registry Number 17167-19: (7*1)+(6*7)+(5*1)+(4*6)+(3*7)+(2*1)+(1*9)=110 110 % 10 = 0 So 17167-19-0 is a valid CAS Registry Number.