442222021 has 2 divisors, whose sum is σ = 442222022. Its totient is φ = 442222020.

The previous prime is 442221977. The next prime is 442222031. The reversal of 442222021 is 120222244.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 442050625 + 171396 = 21025^2 + 414^2 .

It is a cyclic number.

It is not a de Polignac number, because 442222021 - 2⁷ = 442221893 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 442222021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (442222031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 221111010 + 221111011.

It is an arithmetic number, because the mean of its divisors is an integer number (221111011).

Almost surely, 2^442222021 is an apocalyptic number.

It is an amenable number.

442222021 is a deficient number, since it is larger than the sum of its proper divisors (1).

442222021 is an equidigital number, since it uses as much as digits as its factorization.

442222021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 512, while the sum is 19.

The square root of 442222021 is about 21029.0756097362. The cubic root of 442222021 is about 761.8686823491.

Adding to 442222021 its reverse (120222244), we get a palindrome (562444265).

The spelling of 442222021 in words is "four hundred forty-two million, two hundred twenty-two thousand, twenty-one".