20211222112181 has 2 divisors, whose sum is σ = 20211222112182. Its totient is φ = 20211222112180.

The previous prime is 20211222112177. The next prime is 20211222112217. The reversal of 20211222112181 is 18121122211202.

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., 20006163480625 + 205058631556 = 4472825^2 + 452834^2 .

It is a cyclic number.

It is not a de Polignac number, because 20211222112181 - 2² = 20211222112177 is a prime.

It is a super-2 number, since 2×20211222112181² (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 20211222112181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20211222132181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105611056090 + 10105611056091.

It is an arithmetic number, because the mean of its divisors is an integer number (10105611056091).

Almost surely, 2^{20211222112181} is an apocalyptic number.

It is an amenable number.

20211222112181 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211222112181 is an equidigital number, since it uses as much as digits as its factorization.

20211222112181 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 26.

Adding to 20211222112181 its reverse (18121122211202), we get a palindrome (38332344323383).

The spelling of 20211222112181 in words is "twenty trillion, two hundred eleven billion, two hundred twenty-two million, one hundred twelve thousand, one hundred eighty-one".