21091-97-4 Usage
Check Digit Verification of cas no
The CAS Registry Mumber 21091-97-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 2,1,0,9 and 1 respectively; the second part has 2 digits, 9 and 7 respectively.
Calculate Digit Verification of CAS Registry Number 21091-97:
(7*2)+(6*1)+(5*0)+(4*9)+(3*1)+(2*9)+(1*7)=84
84 % 10 = 4
So 21091-97-4 is a valid CAS Registry Number.