213123323221 has 4 divisors (see below), whose sum is σ = 213124368492. Its totient is φ = 213122277952.

The previous prime is 213123323201. The next prime is 213123323227. The reversal of 213123323221 is 122323321312.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 162098838225 + 51024484996 = 402615^2 + 225886^2 .

It is a cyclic number.

It is not a de Polignac number, because 213123323221 - 2¹³ = 213123315029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213123323227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106180 + ... + 661453.

It is an arithmetic number, because the mean of its divisors is an integer number (53281092123).

Almost surely, 2^213123323221 is an apocalyptic number.

It is an amenable number.

213123323221 is a deficient number, since it is larger than the sum of its proper divisors (1045271).

213123323221 is an equidigital number, since it uses as much as digits as its factorization.

213123323221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1045270.

The product of its digits is 2592, while the sum is 25.

Adding to 213123323221 its reverse (122323321312), we get a palindrome (335446644533).

The spelling of 213123323221 in words is "two hundred thirteen billion, one hundred twenty-three million, three hundred twenty-three thousand, two hundred twenty-one".