21991-77-5 Usage
Check Digit Verification of cas no
The CAS Registry Mumber 21991-77-5 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 2,1,9,9 and 1 respectively; the second part has 2 digits, 7 and 7 respectively.
Calculate Digit Verification of CAS Registry Number 21991-77:
(7*2)+(6*1)+(5*9)+(4*9)+(3*1)+(2*7)+(1*7)=125
125 % 10 = 5
So 21991-77-5 is a valid CAS Registry Number.