13243221 has 24 divisors (see below), whose sum is σ = 20478744. Its totient is φ = 8217600.

The previous prime is 13243213. The next prime is 13243253. The reversal of 13243221 is 12234231.

It can be written as a sum of positive squares in 4 ways, for example, as 10400625 + 2842596 = 3225^2 + 1686^2 .

It is not a de Polignac number, because 13243221 - 2³ = 13243213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13243194 and 13243203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13243201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15025 + ... + 15881.

It is an arithmetic number, because the mean of its divisors is an integer number (853281).

Almost surely, 2^13243221 is an apocalyptic number.

It is an amenable number.

13243221 is a deficient number, since it is larger than the sum of its proper divisors (7235523).

13243221 is a wasteful number, since it uses less digits than its factorization.

13243221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 981 (or 978 counting only the distinct ones).

The product of its digits is 288, while the sum is 18.

The square root of 13243221 is about 3639.1236582452. The cubic root of 13243221 is about 236.5908123851.

Adding to 13243221 its reverse (12234231), we get a palindrome (25477452).

The spelling of 13243221 in words is "thirteen million, two hundred forty-three thousand, two hundred twenty-one".