6605221 has 4 divisors (see below), whose sum is σ = 7548832. Its totient is φ = 5661612.

The previous prime is 6605219. The next prime is 6605237. The reversal of 6605221 is 1225066.

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 6605221 - 2¹ = 6605219 is a prime.

It is a Duffinian number.

6605221 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 6605192 and 6605201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6605281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 471795 + ... + 471808.

It is an arithmetic number, because the mean of its divisors is an integer number (1887208).

Almost surely, 2^6605221 is an apocalyptic number.

It is an amenable number.

6605221 is a deficient number, since it is larger than the sum of its proper divisors (943611).

6605221 is an equidigital number, since it uses as much as digits as its factorization.

6605221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 943610.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 6605221 is about 2570.0624506031. The cubic root of 6605221 is about 187.6271942884.

The spelling of 6605221 in words is "six million, six hundred five thousand, two hundred twenty-one".