212101021122181 has 2 divisors, whose sum is σ = 212101021122182. Its totient is φ = 212101021122180.

The previous prime is 212101021122091. The next prime is 212101021122227. The reversal of 212101021122181 is 181221120101212.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 201484795477156 + 10616225645025 = 14194534^2 + 3258255^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212101021122181 is a prime.

It is a super-2 number, since 2×212101021122181² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212101021162181) 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, 106050510561090 + 106050510561091.

It is an arithmetic number, because the mean of its divisors is an integer number (106050510561091).

Almost surely, 2^{212101021122181} is an apocalyptic number.

It is an amenable number.

212101021122181 is a deficient number, since it is larger than the sum of its proper divisors (1).

212101021122181 is an equidigital number, since it uses as much as digits as its factorization.

212101021122181 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 25.

Adding to 212101021122181 its reverse (181221120101212), we get a palindrome (393322141223393).

The spelling of 212101021122181 in words is "two hundred twelve trillion, one hundred one billion, twenty-one million, one hundred twenty-two thousand, one hundred eighty-one".