21010212212281 has 2 divisors, whose sum is σ = 21010212212282. Its totient is φ = 21010212212280.

The previous prime is 21010212212279. The next prime is 21010212212291. The reversal of 21010212212281 is 18221221201012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20870324244025 + 139887968256 = 4568405^2 + 374016^2 .

It is a cyclic number.

It is not a de Polignac number, because 21010212212281 - 2¹ = 21010212212279 is a prime.

It is a super-2 number, since 2×21010212212281² (a number of 27 digits) contains 22 as substring.

Together with 21010212212279, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21010212212291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505106106140 + 10505106106141.

It is an arithmetic number, because the mean of its divisors is an integer number (10505106106141).

Almost surely, 2^{21010212212281} is an apocalyptic number.

It is an amenable number.

21010212212281 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010212212281 is an equidigital number, since it uses as much as digits as its factorization.

21010212212281 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 21010212212281 its reverse (18221221201012), we get a palindrome (39231433413293).

The spelling of 21010212212281 in words is "twenty-one trillion, ten billion, two hundred twelve million, two hundred twelve thousand, two hundred eighty-one".