6600221 has 4 divisors (see below), whose sum is σ = 6761244. Its totient is φ = 6439200.

The previous prime is 6600211. The next prime is 6600227. The reversal of 6600221 is 1220066.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2544025 + 4056196 = 1595^2 + 2014^2 .

It is a cyclic number.

It is not a de Polignac number, because 6600221 - 2⁶ = 6600157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 6600221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6600227) 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, 80450 + ... + 80531.

It is an arithmetic number, because the mean of its divisors is an integer number (1690311).

Almost surely, 2^6600221 is an apocalyptic number.

It is an amenable number.

6600221 is a deficient number, since it is larger than the sum of its proper divisors (161023).

6600221 is a wasteful number, since it uses less digits than its factorization.

6600221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161022.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 6600221 is about 2569.0895274396. The cubic root of 6600221 is about 187.5798391841.

Adding to 6600221 its reverse (1220066), we get a palindrome (7820287).

The spelling of 6600221 in words is "six million, six hundred thousand, two hundred twenty-one".