221221011016021 has 2 divisors, whose sum is σ = 221221011016022. Its totient is φ = 221221011016020.

The previous prime is 221221011015997. The next prime is 221221011016037. The reversal of 221221011016021 is 120610110122122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 166196289857796 + 55024721158225 = 12891714^2 + 7417865^2 .

It is a cyclic number.

It is not a de Polignac number, because 221221011016021 - 2¹⁵ = 221221010983253 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221221011015983 and 221221011016001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221221011016321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110610505508010 + 110610505508011.

It is an arithmetic number, because the mean of its divisors is an integer number (110610505508011).

Almost surely, 2^{221221011016021} is an apocalyptic number.

It is an amenable number.

221221011016021 is a deficient number, since it is larger than the sum of its proper divisors (1).

221221011016021 is an equidigital number, since it uses as much as digits as its factorization.

221221011016021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 22.

Adding to 221221011016021 its reverse (120610110122122), we get a palindrome (341831121138143).

The spelling of 221221011016021 in words is "two hundred twenty-one trillion, two hundred twenty-one billion, eleven million, sixteen thousand, twenty-one".