The CAS Registry Mumber 1186623-49-3 includes 10 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 7 digits, 1,1,8,6,6,2 and 3 respectively; the second part has 2 digits, 4 and 9 respectively. Calculate Digit Verification of CAS Registry Number 1186623-49: (9*1)+(8*1)+(7*8)+(6*6)+(5*6)+(4*2)+(3*3)+(2*4)+(1*9)=173 173 % 10 = 3 So 1186623-49-3 is a valid CAS Registry Number.