• 324 can be written using four 4's:
The square root of 324 is 18.
It is an ABA number since it can be written as A⋅BA, here for A=4, B=3.
It is a nude number because it is divisible by every one of its digits.
It is an Ulam number.
It is a Duffinian number.
It is a plaindrome in base 5, base 13, base 15 and base 16.
It is a nialpdrome in base 3, base 7 and base 9.
It is a zygodrome in base 3 and base 5.
It is an unprimeable number.
324 is an untouchable number, because it is not equal to the sum of proper divisors of any number.
324 is the 18-th square number.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 324
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
324 is a wasteful number, since it uses less digits than its factorization.
324 is an odious number, because the sum of its binary digits is odd.
The cubic root of 324 is about 6.8682854553.
Subtracting from 324 its product of digits (24), we obtain a triangular number (300 = T24).
Multiplying 324 by its product of digits (24), we get a 5-th power (7776 = 65).
Adding to 324 its reverse (423), we get a palindrome (747).
Subtracting 324 from its reverse (423), we obtain a palindrome (99).