13443121 has 4 divisors (see below), whose sum is σ = 13771044. Its totient is φ = 13115200.

The previous prime is 13443113. The next prime is 13443137. The reversal of 13443121 is 12134431.

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 876096 + 12567025 = 936^2 + 3545^2 .

It is a cyclic number.

It is not a de Polignac number, because 13443121 - 2³ = 13443113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13443151) 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, 163900 + ... + 163981.

It is an arithmetic number, because the mean of its divisors is an integer number (3442761).

Almost surely, 2^13443121 is an apocalyptic number.

It is an amenable number.

13443121 is a deficient number, since it is larger than the sum of its proper divisors (327923).

13443121 is an equidigital number, since it uses as much as digits as its factorization.

13443121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327922.

The product of its digits is 288, while the sum is 19.

The square root of 13443121 is about 3666.4861925282. The cubic root of 13443121 is about 237.7752804366.

Adding to 13443121 its reverse (12134431), we get a palindrome (25577552).

It can be divided in two parts, 1344 and 3121, that added together give a triangular number (4465 = T₉₄).

The spelling of 13443121 in words is "thirteen million, four hundred forty-three thousand, one hundred twenty-one".