212612216221 has 2 divisors, whose sum is σ = 212612216222. Its totient is φ = 212612216220.

The previous prime is 212612216111. The next prime is 212612216233. The reversal of 212612216221 is 122612216212.

It is a happy number.

212612216221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 145214344900 + 67397871321 = 381070^2 + 259611^2 .

It is a cyclic number.

It is not a de Polignac number, because 212612216221 - 2⁷ = 212612216093 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 212612216221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212612211221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106306108110 + 106306108111.

It is an arithmetic number, because the mean of its divisors is an integer number (106306108111).

Almost surely, 2^212612216221 is an apocalyptic number.

It is an amenable number.

212612216221 is a deficient number, since it is larger than the sum of its proper divisors (1).

212612216221 is an equidigital number, since it uses as much as digits as its factorization.

212612216221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2304, while the sum is 28.

Subtracting from 212612216221 its reverse (122612216212), we obtain a palindrome (90000000009).

The spelling of 212612216221 in words is "two hundred twelve billion, six hundred twelve million, two hundred sixteen thousand, two hundred twenty-one".