13443121421 has 2 divisors, whose sum is σ = 13443121422. Its totient is φ = 13443121420.

The previous prime is 13443121403. The next prime is 13443121427. The reversal of 13443121421 is 12412134431.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11328409225 + 2114712196 = 106435^2 + 45986^2 .

It is an emirp because it is prime and its reverse (12412134431) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 13443121421 - 2¹⁴ = 13443105037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13443121427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6721560710 + 6721560711.

It is an arithmetic number, because the mean of its divisors is an integer number (6721560711).

Almost surely, 2^13443121421 is an apocalyptic number.

It is an amenable number.

13443121421 is a deficient number, since it is larger than the sum of its proper divisors (1).

13443121421 is an equidigital number, since it uses as much as digits as its factorization.

13443121421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2304, while the sum is 26.

Adding to 13443121421 its reverse (12412134431), we get a palindrome (25855255852).

The spelling of 13443121421 in words is "thirteen billion, four hundred forty-three million, one hundred twenty-one thousand, four hundred twenty-one".