6671221 has 4 divisors (see below), whose sum is σ = 6695244. Its totient is φ = 6647200.

The previous prime is 6671201. The next prime is 6671239. The reversal of 6671221 is 1221766.

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 5948721 + 722500 = 2439^2 + 850^2 .

It is a cyclic number.

It is not a de Polignac number, because 6671221 - 2⁹ = 6670709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6671201) 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, 11590 + ... + 12151.

It is an arithmetic number, because the mean of its divisors is an integer number (1673811).

Almost surely, 2^6671221 is an apocalyptic number.

It is an amenable number.

6671221 is a deficient number, since it is larger than the sum of its proper divisors (24023).

6671221 is a wasteful number, since it uses less digits than its factorization.

6671221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24022.

The product of its digits is 1008, while the sum is 25.

The square root of 6671221 is about 2582.8706897559. The cubic root of 6671221 is about 188.2500539380.

Adding to 6671221 its reverse (1221766), we get a palindrome (7892987).

The spelling of 6671221 in words is "six million, six hundred seventy-one thousand, two hundred twenty-one".