21110020202021 has 2 divisors, whose sum is σ = 21110020202022. Its totient is φ = 21110020202020.

The previous prime is 21110020201997. The next prime is 21110020202053. The reversal of 21110020202021 is 12020202001112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15767935624996 + 5342084577025 = 3970886^2 + 2311295^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21110020202021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21110020201987 and 21110020202005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21110020202081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555010101010 + 10555010101011.

It is an arithmetic number, because the mean of its divisors is an integer number (10555010101011).

Almost surely, 2^{21110020202021} is an apocalyptic number.

It is an amenable number.

21110020202021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21110020202021 is an equidigital number, since it uses as much as digits as its factorization.

21110020202021 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 21110020202021 its reverse (12020202001112), we get a palindrome (33130222203133).

The spelling of 21110020202021 in words is "twenty-one trillion, one hundred ten billion, twenty million, two hundred two thousand, twenty-one".