21638-89-1 Usage
Check Digit Verification of cas no
The CAS Registry Mumber 21638-89-1 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 2,1,6,3 and 8 respectively; the second part has 2 digits, 8 and 9 respectively.
Calculate Digit Verification of CAS Registry Number 21638-89:
(7*2)+(6*1)+(5*6)+(4*3)+(3*8)+(2*8)+(1*9)=111
111 % 10 = 1
So 21638-89-1 is a valid CAS Registry Number.