442644221 has 2 divisors, whose sum is σ = 442644222. Its totient is φ = 442644220.

The previous prime is 442644203. The next prime is 442644247. The reversal of 442644221 is 122446244.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 438441721 + 4202500 = 20939^2 + 2050^2 .

It is a cyclic number.

It is not a de Polignac number, because 442644221 - 2¹⁸ = 442382077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (442644421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 221322110 + 221322111.

It is an arithmetic number, because the mean of its divisors is an integer number (221322111).

Almost surely, 2^442644221 is an apocalyptic number.

It is an amenable number.

442644221 is a deficient number, since it is larger than the sum of its proper divisors (1).

442644221 is an equidigital number, since it uses as much as digits as its factorization.

442644221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12288, while the sum is 29.

The square root of 442644221 is about 21039.1116970275. Note that the first 3 decimals coincide. The cubic root of 442644221 is about 762.1110633484. Note that the first 3 decimals are identical.

The spelling of 442644221 in words is "four hundred forty-two million, six hundred forty-four thousand, two hundred twenty-one".