212221022161 has 2 divisors, whose sum is σ = 212221022162. Its totient is φ = 212221022160.

The previous prime is 212221022099. The next prime is 212221022191. The reversal of 212221022161 is 161220122212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 190581141136 + 21639881025 = 436556^2 + 147105^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212221022161 is a prime.

It is not a weakly prime, because it can be changed into another prime (212221022191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106110511080 + 106110511081.

It is an arithmetic number, because the mean of its divisors is an integer number (106110511081).

Almost surely, 2^212221022161 is an apocalyptic number.

It is an amenable number.

212221022161 is a deficient number, since it is larger than the sum of its proper divisors (1).

212221022161 is an equidigital number, since it uses as much as digits as its factorization.

212221022161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 384, while the sum is 22.

Adding to 212221022161 its reverse (161220122212), we get a palindrome (373441144373).

The spelling of 212221022161 in words is "two hundred twelve billion, two hundred twenty-one million, twenty-two thousand, one hundred sixty-one".