Divisor 3343
- Prime Number:
 - Yes!
 - Divisibility test:
 - The "Austin Howard Test"
 - Test Discovered by:
 - Matt Parker
 - Date:
 - 11/11/2024
 
The "Austin Howard Test" for Divisibility by 3343
To determine if any number is divisible by 3343, apply the "Austin Howard Test":
- If your number ("X") has 5 digits or more, separate the last (smallest) 4 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 5 digits, L = 0 and therefore R = X.
 - Multiply L by 29 and subtract this from R.
 - Take that result and cross off its final digit (units). Take this new number and add 1003 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 3343. That is, your original number is divisible by 3343 if (and only if) Y is. Now that it's much smaller, with basic knowledge of your 3343-times tables, it should be easy to visually see if Y is divisible by 3343. If the Y is still much larger than 3343, the above process can be repeated until it does reduce to within small multiples of 3343.
 
Easy!