12213121421 has 4 divisors (see below), whose sum is σ = 12213645600. Its totient is φ = 12212597244.

The previous prime is 12213121391. The next prime is 12213121439. The reversal of 12213121421 is 12412131221.

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.

It is a cyclic number.

It is not a de Polignac number, because 12213121421 - 2²² = 12208927117 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 12213121393 and 12213121402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12213121471) 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, 225431 + ... + 274308.

It is an arithmetic number, because the mean of its divisors is an integer number (3053411400).

Almost surely, 2^12213121421 is an apocalyptic number.

It is an amenable number.

12213121421 is a deficient number, since it is larger than the sum of its proper divisors (524179).

12213121421 is an equidigital number, since it uses as much as digits as its factorization.

12213121421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 524178.

The product of its digits is 192, while the sum is 20.

Adding to 12213121421 its reverse (12412131221), we get a palindrome (24625252642).

The spelling of 12213121421 in words is "twelve billion, two hundred thirteen million, one hundred twenty-one thousand, four hundred twenty-one".