6446221 has 2 divisors, whose sum is σ = 6446222. Its totient is φ = 6446220.

The previous prime is 6446203. The next prime is 6446227. The reversal of 6446221 is 1226446.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6320196 + 126025 = 2514^2 + 355^2 .

It is a cyclic number.

It is not a de Polignac number, because 6446221 - 2⁵ = 6446189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6446227) 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 as a sum of consecutive naturals, namely, 3223110 + 3223111.

It is an arithmetic number, because the mean of its divisors is an integer number (3223111).

Almost surely, 2^6446221 is an apocalyptic number.

It is an amenable number.

6446221 is a deficient number, since it is larger than the sum of its proper divisors (1).

6446221 is an equidigital number, since it uses as much as digits as its factorization.

6446221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2304, while the sum is 25.

The square root of 6446221 is about 2538.9409209353. The cubic root of 6446221 is about 186.1094376589.

The spelling of 6446221 in words is "six million, four hundred forty-six thousand, two hundred twenty-one".