20211111202021 has 2 divisors, whose sum is σ = 20211111202022. Its totient is φ = 20211111202020.

The previous prime is 20211111201977. The next prime is 20211111202027. The reversal of 20211111202021 is 12020211111202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16918661032900 + 3292450169121 = 4113230^2 + 1814511^2 .

It is a cyclic number.

It is not a de Polignac number, because 20211111202021 - 2¹⁷ = 20211111070949 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20211111201986 and 20211111202004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20211111202027) 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, 10105555601010 + 10105555601011.

It is an arithmetic number, because the mean of its divisors is an integer number (10105555601011).

Almost surely, 2^{20211111202021} is an apocalyptic number.

It is an amenable number.

20211111202021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211111202021 is an equidigital number, since it uses as much as digits as its factorization.

20211111202021 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 16.

Adding to 20211111202021 its reverse (12020211111202), we get a palindrome (32231322313223).

The spelling of 20211111202021 in words is "twenty trillion, two hundred eleven billion, one hundred eleven million, two hundred two thousand, twenty-one".