21002011002221 has 2 divisors, whose sum is σ = 21002011002222. Its totient is φ = 21002011002220.

The previous prime is 21002011002211. The next prime is 21002011002233. The reversal of 21002011002221 is 12220011020012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18632301745225 + 2369709256996 = 4316515^2 + 1539386^2 .

It is a cyclic number.

It is not a de Polignac number, because 21002011002221 - 2³⁴ = 20984831133037 is a prime.

It is a super-2 number, since 2×21002011002221² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21002011002196 and 21002011002205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21002011002211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501005501110 + 10501005501111.

It is an arithmetic number, because the mean of its divisors is an integer number (10501005501111).

Almost surely, 2^{21002011002221} is an apocalyptic number.

It is an amenable number.

21002011002221 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002011002221 is an equidigital number, since it uses as much as digits as its factorization.

21002011002221 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 21002011002221 its reverse (12220011020012), we get a palindrome (33222022022233).

The spelling of 21002011002221 in words is "twenty-one trillion, two billion, eleven million, two thousand, two hundred twenty-one".