all my digits are different the product of my digits is not equal to zero all of my digits are square numbers my units digit is even i am less than 500

The correct answer is 194

Step-by-step explanation:

let us check the answer against the criteria given in the question to check if they are correct:

a) all my digits are different: 1, 9 and 4 are all different digits

b) the product of my digits is not equal to zero: 1 * 9 * 4 = 36 ≠ 0

c) all my digits are square numbers: 1, 9 and 4 are all square numbers, having the square-root of 1, 3 and 2 respectively.

d) my units digit is even : the units digit in '194' is '4' and it is an even number

e) i am less than 500 : 194 is less than 500

Therefore the number is 194.