21210122210281 has 2 divisors, whose sum is σ = 21210122210282. Its totient is φ = 21210122210280.

The previous prime is 21210122210171. The next prime is 21210122210311. The reversal of 21210122210281 is 18201222101212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16881292429225 + 4328829781056 = 4108685^2 + 2080584^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210122210281 - 2⁹ = 21210122209769 is a prime.

It is a super-2 number, since 2×21210122210281² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21210122510281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605061105140 + 10605061105141.

It is an arithmetic number, because the mean of its divisors is an integer number (10605061105141).

Almost surely, 2^{21210122210281} is an apocalyptic number.

It is an amenable number.

21210122210281 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210122210281 is an equidigital number, since it uses as much as digits as its factorization.

21210122210281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 512, while the sum is 25.

Adding to 21210122210281 its reverse (18201222101212), we get a palindrome (39411344311493).

The spelling of 21210122210281 in words is "twenty-one trillion, two hundred ten billion, one hundred twenty-two million, two hundred ten thousand, two hundred eighty-one".