12123323221 has 4 divisors (see below), whose sum is σ = 12151322092. Its totient is φ = 12095324352.

The previous prime is 12123323213. The next prime is 12123323243. The reversal of 12123323221 is 12232332121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12232332121 = 23 ⋅531840527.

It can be written as a sum of positive squares in 2 ways, for example, as 2457680625 + 9665642596 = 49575^2 + 98314^2 .

It is a cyclic number.

It is not a de Polignac number, because 12123323221 - 2³ = 12123323213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12123323192 and 12123323201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12123323291) 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 in 3 ways as a sum of consecutive naturals, for example, 13998786 + ... + 13999651.

It is an arithmetic number, because the mean of its divisors is an integer number (3037830523).

Almost surely, 2^12123323221 is an apocalyptic number.

It is an amenable number.

12123323221 is a deficient number, since it is larger than the sum of its proper divisors (27998871).

12123323221 is an equidigital number, since it uses as much as digits as its factorization.

12123323221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27998870.

The product of its digits is 864, while the sum is 22.

Adding to 12123323221 its reverse (12232332121), we get a palindrome (24355655342).

The spelling of 12123323221 in words is "twelve billion, one hundred twenty-three million, three hundred twenty-three thousand, two hundred twenty-one".