2721223 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
It is a strong prime.
It is a cyclic number.
It is a de Polignac number, because none of the positive numbers 2k-2721223 is a prime.
It is a self number, because there is not a number n which added to its sum of digits gives 2721223.
It is a congruent number.
22721223 is an apocalyptic number.
2721223 is an equidigital number, since it uses as much as digits as its factorization.
2721223 is an odious number, because the sum of its binary digits is odd.
The square root of 2721223 is about 1649.6129849149. The cubic root of 2721223 is about 139.6115592927.
Adding to 2721223 its reverse (3221272), we get a palindrome (5942495).
The spelling of 2721223 in words is "two million, seven hundred twenty-one thousand, two hundred twenty-three".