21009-91-6 Usage
Check Digit Verification of cas no
The CAS Registry Mumber 21009-91-6 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 2,1,0,0 and 9 respectively; the second part has 2 digits, 9 and 1 respectively.
Calculate Digit Verification of CAS Registry Number 21009-91:
(7*2)+(6*1)+(5*0)+(4*0)+(3*9)+(2*9)+(1*1)=66
66 % 10 = 6
So 21009-91-6 is a valid CAS Registry Number.