2123 is an esthetic number in base 10, because in such base its adjacent digits differ by 1.
It is a semiprime because it is the product of two primes.
It is a cyclic number.
It is an alternating number because its digits alternate between even and odd.
It is a Duffinian number.
It is a plaindrome in base 6 and base 12.
It is a nialpdrome in base 13.
It is a self number, because there is not a number n which added to its sum of digits gives 2123.
22123 is an apocalyptic number.
2123 is a wasteful number, since it uses less digits than its factorization.
2123 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 204.
The square root of 2123 is about 46.0760241340. The cubic root of 2123 is about 12.8523733044.
Adding to 2123 its reverse (3212), we get a palindrome (5335).
Subtracting 2123 from its reverse (3212), we obtain a square (1089 = 332).
The spelling of 2123 in words is "two thousand, one hundred twenty-three", and thus it is an iban number.