Bank uses checksum algorithm to prevent this

Say your acc num : 1112355640

11 (bank) 123 (branch) 556 (acc num) 40 (checksum)

Account number must return a round number when divided by a preset number, i.e. 88

So 1112355640 / 88 must = 12640405

Next random acc num: 1112355728 https://twitter.com/f15teen15/status/1352263630629134341

So if 3 person registers new account at the same branch together their account numbers are

1112355640, 1112355728, 1112355816 ...

To key in the wrong number your chances are 1 in 1000 (0.0010)

Your chances of winning the Magnum4D is 2.3 times higher at 23 in 10,000 (0.0023)

In computer engineering they apply the infamous "Murphy's Law"

If there's anything that can go wrong, an idiot will do it wrongly.