16561-91-4 Usage
Check Digit Verification of cas no
The CAS Registry Mumber 16561-91-4 includes 8 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 5 digits, 1,6,5,6 and 1 respectively; the second part has 2 digits, 9 and 1 respectively.
Calculate Digit Verification of CAS Registry Number 16561-91:
(7*1)+(6*6)+(5*5)+(4*6)+(3*1)+(2*9)+(1*1)=114
114 % 10 = 4
So 16561-91-4 is a valid CAS Registry Number.