The CAS Registry Mumber 53619-17-3 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 5,3,6,1 and 9 respectively; the second part has 2 digits, 1 and 7 respectively. Calculate Digit Verification of CAS Registry Number 53619-17: (7*5)+(6*3)+(5*6)+(4*1)+(3*9)+(2*1)+(1*7)=123 123 % 10 = 3 So 53619-17-3 is a valid CAS Registry Number.