221442304021 has 2 divisors, whose sum is σ = 221442304022. Its totient is φ = 221442304020.

The previous prime is 221442304009. The next prime is 221442304037. The reversal of 221442304021 is 120403244122.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 162478323396 + 58963980625 = 403086^2 + 242825^2 .

It is a cyclic number.

It is not a de Polignac number, because 221442304021 - 2⁷ = 221442303893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221442304091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110721152010 + 110721152011.

It is an arithmetic number, because the mean of its divisors is an integer number (110721152011).

Almost surely, 2^221442304021 is an apocalyptic number.

It is an amenable number.

221442304021 is a deficient number, since it is larger than the sum of its proper divisors (1).

221442304021 is an equidigital number, since it uses as much as digits as its factorization.

221442304021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3072, while the sum is 25.

Adding to 221442304021 its reverse (120403244122), we get a palindrome (341845548143).

The spelling of 221442304021 in words is "two hundred twenty-one billion, four hundred forty-two million, three hundred four thousand, twenty-one".