Divisor 2809
- Prime Number:
- No, but it is a power of a prime: 532
Test for Divisibility by 2809
To determine if any number is divisible by 2809, apply this test:
- If your number ("X") has 7 digits or more, separate the last (smallest) 6 digits from the rest. This makes two smaller numbers, call them Left and Right (note: don't add in trailing zeros to L). If there are fewer than 7 digits, L = 0 and therefore R = X.
- Multiply L by 4 and subtract this from R.
- Take that result and cross off its final digit (units). Take this new number and add 281 times the digit you just crossed off. Call this final result "Y".
- Y will be much smaller than X, but we have preserved divisibility by 2809. That is, your original number is divisible by 2809 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 2809-times tables, it should be easy to visually see if Y is divisible by 2809. If the Y is still much larger than 2809, the above process can be repeated until it does reduce to within small multiples of 2809.
Easy!