21122210211281 has 2 divisors, whose sum is σ = 21122210211282. Its totient is φ = 21122210211280.

The previous prime is 21122210211259. The next prime is 21122210211371. The reversal of 21122210211281 is 18211201222112.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20900760910225 + 221449301056 = 4571735^2 + 470584^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21122210211281 is a prime.

It is a super-2 number, since 2×21122210211281² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21122210211281.

It is not a weakly prime, because it can be changed into another prime (21122210211181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561105105640 + 10561105105641.

It is an arithmetic number, because the mean of its divisors is an integer number (10561105105641).

Almost surely, 2^{21122210211281} is an apocalyptic number.

It is an amenable number.

21122210211281 is a deficient number, since it is larger than the sum of its proper divisors (1).

21122210211281 is an equidigital number, since it uses as much as digits as its factorization.

21122210211281 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 512, while the sum is 26.

Adding to 21122210211281 its reverse (18211201222112), we get a palindrome (39333411433393).

The spelling of 21122210211281 in words is "twenty-one trillion, one hundred twenty-two billion, two hundred ten million, two hundred eleven thousand, two hundred eighty-one".