6553221 has 4 divisors (see below), whose sum is σ = 8737632. Its totient is φ = 4368812.

The previous prime is 6553219. The next prime is 6553231. The reversal of 6553221 is 1223556.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6553221 - 2¹ = 6553219 is a prime.

It is a D-number.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 6553191 and 6553200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6553231) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1092201 + ... + 1092206.

It is an arithmetic number, because the mean of its divisors is an integer number (2184408).

Almost surely, 2^6553221 is an apocalyptic number.

It is an amenable number.

6553221 is a deficient number, since it is larger than the sum of its proper divisors (2184411).

6553221 is a wasteful number, since it uses less digits than its factorization.

6553221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2184410.

The product of its digits is 1800, while the sum is 24.

The square root of 6553221 is about 2559.9259754923. The cubic root of 6553221 is about 187.1335277453.

Adding to 6553221 its reverse (1223556), we get a palindrome (7776777).

The spelling of 6553221 in words is "six million, five hundred fifty-three thousand, two hundred twenty-one".