1211120221 has 2 divisors, whose sum is σ = 1211120222. Its totient is φ = 1211120220.

The previous prime is 1211120213. The next prime is 1211120227. The reversal of 1211120221 is 1220211121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 923308996 + 287811225 = 30386^2 + 16965^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211120221 - 2³ = 1211120213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211120227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605560110 + 605560111.

It is an arithmetic number, because the mean of its divisors is an integer number (605560111).

Almost surely, 2^1211120221 is an apocalyptic number.

It is an amenable number.

1211120221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211120221 is an equidigital number, since it uses as much as digits as its factorization.

1211120221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 1211120221 is about 34801.1525814879. The cubic root of 1211120221 is about 1065.9309810676.

Adding to 1211120221 its reverse (1220211121), we get a palindrome (2431331342).

The spelling of 1211120221 in words is "one billion, two hundred eleven million, one hundred twenty thousand, two hundred twenty-one".