13281321 has 4 divisors (see below), whose sum is σ = 17708432. Its totient is φ = 8854212.

The previous prime is 13281293. The next prime is 13281329. The reversal of 13281321 is 12318231.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12318231 = 3 ⋅4106077.

It is not a de Polignac number, because 13281321 - 2⁷ = 13281193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13281329) 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, 2213551 + ... + 2213556.

It is an arithmetic number, because the mean of its divisors is an integer number (4427108).

Almost surely, 2^13281321 is an apocalyptic number.

It is an amenable number.

13281321 is a deficient number, since it is larger than the sum of its proper divisors (4427111).

13281321 is an equidigital number, since it uses as much as digits as its factorization.

13281321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4427110.

The product of its digits is 288, while the sum is 21.

The square root of 13281321 is about 3644.3546753849. The cubic root of 13281321 is about 236.8174812944.

Adding to 13281321 its reverse (12318231), we get a palindrome (25599552).

The spelling of 13281321 in words is "thirteen million, two hundred eighty-one thousand, three hundred twenty-one".