21220102222021 has 2 divisors, whose sum is σ = 21220102222022. Its totient is φ = 21220102222020.

The previous prime is 21220102221977. The next prime is 21220102222031. The reversal of 21220102222021 is 12022220102212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16340593522500 + 4879508699521 = 4042350^2 + 2208961^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21220102222021 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21220102222021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21220102222031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610051111010 + 10610051111011.

It is an arithmetic number, because the mean of its divisors is an integer number (10610051111011).

Almost surely, 2^{21220102222021} is an apocalyptic number.

It is an amenable number.

21220102222021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220102222021 is an equidigital number, since it uses as much as digits as its factorization.

21220102222021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 21220102222021 its reverse (12022220102212), we get a palindrome (33242322324233).

The spelling of 21220102222021 in words is "twenty-one trillion, two hundred twenty billion, one hundred two million, two hundred twenty-two thousand, twenty-one".