81639-20-5 Usage
Check Digit Verification of cas no
The CAS Registry Mumber 81639-20-5 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 8,1,6,3 and 9 respectively; the second part has 2 digits, 2 and 0 respectively.
Calculate Digit Verification of CAS Registry Number 81639-20:
(7*8)+(6*1)+(5*6)+(4*3)+(3*9)+(2*2)+(1*0)=135
135 % 10 = 5
So 81639-20-5 is a valid CAS Registry Number.