212031321221 has 2 divisors, whose sum is σ = 212031321222. Its totient is φ = 212031321220.

The previous prime is 212031321197. The next prime is 212031321241. The reversal of 212031321221 is 122123130212.

It is an a-pointer prime, because the next prime (212031321241) can be obtained adding 212031321221 to its sum of digits (20).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 206538436225 + 5492884996 = 454465^2 + 74114^2 .

It is a cyclic number.

It is not a de Polignac number, because 212031321221 - 2¹⁰ = 212031320197 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 212031321193 and 212031321202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212031321241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106015660610 + 106015660611.

It is an arithmetic number, because the mean of its divisors is an integer number (106015660611).

Almost surely, 2^212031321221 is an apocalyptic number.

It is an amenable number.

212031321221 is a deficient number, since it is larger than the sum of its proper divisors (1).

212031321221 is an equidigital number, since it uses as much as digits as its factorization.

212031321221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 212031321221 its reverse (122123130212), we get a palindrome (334154451433).

The spelling of 212031321221 in words is "two hundred twelve billion, thirty-one million, three hundred twenty-one thousand, two hundred twenty-one".