13121433421 has 6 divisors (see below), whose sum is σ = 13848383022. Its totient is φ = 12430831320.

The previous prime is 13121433343. The next prime is 13121433449. The reversal of 13121433421 is 12433412131.

13121433421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 9352824100 + 3768609321 = 96710^2 + 61389^2 .

It is not a de Polignac number, because 13121433421 - 2²⁷ = 12987215693 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 (13121437421) 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 5 ways as a sum of consecutive naturals, for example, 18173370 + ... + 18174091.

It is an arithmetic number, because the mean of its divisors is an integer number (2308063837).

Almost surely, 2^13121433421 is an apocalyptic number.

It is an amenable number.

13121433421 is a deficient number, since it is larger than the sum of its proper divisors (726949601).

13121433421 is an equidigital number, since it uses as much as digits as its factorization.

13121433421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36347499 (or 36347480 counting only the distinct ones).

The product of its digits is 1728, while the sum is 25.

Adding to 13121433421 its reverse (12433412131), we get a palindrome (25554845552).

The spelling of 13121433421 in words is "thirteen billion, one hundred twenty-one million, four hundred thirty-three thousand, four hundred twenty-one".