Neither.
The number 831 is neither a straight nor a leopard. The leopard refers to the three numbers with the same ending. The three numbers of 831 are different. The straight is a continuous string of numbers. 831 is not a continuous number.
Shunzi number, Leopard number is, Shunzi number, Shunzi number refers to consecutive Arabic numerals, such as 123, 789 format, folding purpose, generally reflected in the license plate number, easy to remember, Moreover, getting a straight number also becomes an individual's social activity ability.