It is a happy number.
4545 is nontrivially palindromic in base 8.
4545 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.
It is an alternating number because its digits alternate between even and odd.
4545 is an undulating number in base 10.
It is a Curzon number.
It is a nialpdrome in base 9.
It is a congruent number.
24545 is an apocalyptic number.
4545 is a gapful number since it is divisible by the number (45) formed by its first and last digit.
It is an amenable number.
4545 is a wasteful number, since it uses less digits than its factorization.
4545 is an odious number, because the sum of its binary digits is odd.
The square root of 4545 is about 67.4166151627. The cubic root of 4545 is about 16.5644859373.
Multiplying 4545 by its sum of digits (18), we get a triangular number (81810 = T404).
Adding to 4545 its reverse (5454), we get a palindrome (9999).
Subtracting 4545 from its reverse (5454), we obtain a palindrome (909).
The spelling of 4545 in words is "four thousand, five hundred forty-five".