1021211120021 has 2 divisors, whose sum is σ = 1021211120022. Its totient is φ = 1021211120020.

The previous prime is 1021211119997. The next prime is 1021211120071. The reversal of 1021211120021 is 1200211121201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 819866866225 + 201344253796 = 905465^2 + 448714^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021211120021 - 2¹⁰ = 1021211118997 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1021211119978 and 1021211120005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021211120071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510605560010 + 510605560011.

It is an arithmetic number, because the mean of its divisors is an integer number (510605560011).

Almost surely, 2^{1021211120021} is an apocalyptic number.

It is an amenable number.

1021211120021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021211120021 is an equidigital number, since it uses as much as digits as its factorization.

1021211120021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1021211120021 its reverse (1200211121201), we get a palindrome (2221422241222).

The spelling of 1021211120021 in words is "one trillion, twenty-one billion, two hundred eleven million, one hundred twenty thousand, twenty-one".