12321312221 has 4 divisors (see below), whose sum is σ = 12857021472. Its totient is φ = 11785602972.

The previous prime is 12321312203. The next prime is 12321312229. The reversal of 12321312221 is 12221312321.

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: 12221312321 = 4243 ⋅2880347.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12321312221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12321312193 and 12321312202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12321312229) 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, 267854591 + ... + 267854636.

It is an arithmetic number, because the mean of its divisors is an integer number (3214255368).

Almost surely, 2^12321312221 is an apocalyptic number.

It is an amenable number.

12321312221 is a deficient number, since it is larger than the sum of its proper divisors (535709251).

12321312221 is an equidigital number, since it uses as much as digits as its factorization.

12321312221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 535709250.

The product of its digits is 288, while the sum is 20.

Adding to 12321312221 its reverse (12221312321), we get a palindrome (24542624542).

The spelling of 12321312221 in words is "twelve billion, three hundred twenty-one million, three hundred twelve thousand, two hundred twenty-one".