1021201220021 has 2 divisors, whose sum is σ = 1021201220022. Its totient is φ = 1021201220020.

The previous prime is 1021201219981. The next prime is 1021201220023. The reversal of 1021201220021 is 1200221021201.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 526691290225 + 494509929796 = 725735^2 + 703214^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021201220021 - 2¹⁴ = 1021201203637 is a prime.

Together with 1021201220023, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1021201219978 and 1021201220005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021201220023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510600610010 + 510600610011.

It is an arithmetic number, because the mean of its divisors is an integer number (510600610011).

Almost surely, 2^{1021201220021} is an apocalyptic number.

It is an amenable number.

1021201220021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021201220021 is an equidigital number, since it uses as much as digits as its factorization.

1021201220021 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 1021201220021 its reverse (1200221021201), we get a palindrome (2221422241222).

The spelling of 1021201220021 in words is "one trillion, twenty-one billion, two hundred one million, two hundred twenty thousand, twenty-one".