221021012021 has 2 divisors, whose sum is σ = 221021012022. Its totient is φ = 221021012020.

The previous prime is 221021011999. The next prime is 221021012041. The reversal of 221021012021 is 120210120122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 200000361796 + 21020650225 = 447214^2 + 144985^2 .

It is a cyclic number.

It is not a de Polignac number, because 221021012021 - 2⁶ = 221021011957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221021011987 and 221021012005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221021012041) 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, 110510506010 + 110510506011.

It is an arithmetic number, because the mean of its divisors is an integer number (110510506011).

Almost surely, 2^221021012021 is an apocalyptic number.

It is an amenable number.

221021012021 is a deficient number, since it is larger than the sum of its proper divisors (1).

221021012021 is an equidigital number, since it uses as much as digits as its factorization.

221021012021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 221021012021 its reverse (120210120122), we get a palindrome (341231132143).

The spelling of 221021012021 in words is "two hundred twenty-one billion, twenty-one million, twelve thousand, twenty-one".