12423123221 has 4 divisors (see below), whose sum is σ = 12424181952. Its totient is φ = 12422064492.

The previous prime is 12423123187. The next prime is 12423123227. The reversal of 12423123221 is 12232132421.

12423123221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12232132421 = 61 ⋅200526761.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12423123221 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 (12423123227) 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, 511565 + ... + 535298.

It is an arithmetic number, because the mean of its divisors is an integer number (3106045488).

Almost surely, 2^12423123221 is an apocalyptic number.

It is an amenable number.

12423123221 is a deficient number, since it is larger than the sum of its proper divisors (1058731).

12423123221 is a wasteful number, since it uses less digits than its factorization.

12423123221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1058730.

The product of its digits is 1152, while the sum is 23.

Adding to 12423123221 its reverse (12232132421), we get a palindrome (24655255642).

The spelling of 12423123221 in words is "twelve billion, four hundred twenty-three million, one hundred twenty-three thousand, two hundred twenty-one".