13443423221 has 4 divisors (see below), whose sum is σ = 13443812844. Its totient is φ = 13443033600.

The previous prime is 13443423209. The next prime is 13443423223. The reversal of 13443423221 is 12232434431.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11653202500 + 1790220721 = 107950^2 + 42311^2 .

It is a cyclic number.

It is not a de Polignac number, because 13443423221 - 2²² = 13439228917 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 (13443423223) 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, 137420 + ... + 213941.

It is an arithmetic number, because the mean of its divisors is an integer number (3360953211).

Almost surely, 2^13443423221 is an apocalyptic number.

It is an amenable number.

13443423221 is a deficient number, since it is larger than the sum of its proper divisors (389623).

13443423221 is an equidigital number, since it uses as much as digits as its factorization.

13443423221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 389622.

The product of its digits is 13824, while the sum is 29.

Adding to 13443423221 its reverse (12232434431), we get a palindrome (25675857652).

The spelling of 13443423221 in words is "thirteen billion, four hundred forty-three million, four hundred twenty-three thousand, two hundred twenty-one".