21020202022021 has 2 divisors, whose sum is σ = 21020202022022. Its totient is φ = 21020202022020.

The previous prime is 21020202022003. The next prime is 21020202022093. The reversal of 21020202022021 is 12022020202012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19473377508225 + 1546824513796 = 4412865^2 + 1243714^2 .

It is a cyclic number.

It is not a de Polignac number, because 21020202022021 - 2²⁵ = 21020168467589 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21020202021986 and 21020202022004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21020202022121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510101011010 + 10510101011011.

It is an arithmetic number, because the mean of its divisors is an integer number (10510101011011).

Almost surely, 2^{21020202022021} is an apocalyptic number.

It is an amenable number.

21020202022021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020202022021 is an equidigital number, since it uses as much as digits as its factorization.

21020202022021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 128, while the sum is 16.

Adding to 21020202022021 its reverse (12022020202012), we get a palindrome (33042222224033).

The spelling of 21020202022021 in words is "twenty-one trillion, twenty billion, two hundred two million, twenty-two thousand, twenty-one".