1211223230221 has 4 divisors (see below), whose sum is σ = 1211542565212. Its totient is φ = 1210903895232.

The previous prime is 1211223230183. The next prime is 1211223230233. The reversal of 1211223230221 is 1220323221121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 413434854121 + 797788376100 = 642989^2 + 893190^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211223230221 - 2³¹ = 1209075746573 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211223230192 and 1211223230201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211223230251) 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 in 3 ways as a sum of consecutive naturals, for example, 159661806 + ... + 159669391.

It is an arithmetic number, because the mean of its divisors is an integer number (302885641303).

Almost surely, 2^{1211223230221} is an apocalyptic number.

It is an amenable number.

1211223230221 is a deficient number, since it is larger than the sum of its proper divisors (319334991).

1211223230221 is an equidigital number, since it uses as much as digits as its factorization.

1211223230221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319334990.

The product of its (nonzero) digits is 576, while the sum is 22.

Adding to 1211223230221 its reverse (1220323221121), we get a palindrome (2431546451342).

The spelling of 1211223230221 in words is "one trillion, two hundred eleven billion, two hundred twenty-three million, two hundred thirty thousand, two hundred twenty-one".