13440521 has 4 divisors (see below), whose sum is σ = 13453332. Its totient is φ = 13427712.

The previous prime is 13440473. The next prime is 13440529. The reversal of 13440521 is 12504431.

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 10240000 + 3200521 = 3200^2 + 1789^2 .

It is a cyclic number.

It is not a de Polignac number, because 13440521 - 2¹⁰ = 13439497 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13440493 and 13440502.

It is not an unprimeable number, because it can be changed into a prime (13440529) 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, 4676 + ... + 6981.

It is an arithmetic number, because the mean of its divisors is an integer number (3363333).

Almost surely, 2^13440521 is an apocalyptic number.

It is an amenable number.

13440521 is a deficient number, since it is larger than the sum of its proper divisors (12811).

13440521 is a wasteful number, since it uses less digits than its factorization.

13440521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12810.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 13440521 is about 3666.1316124766. The cubic root of 13440521 is about 237.7599502765.

Adding to 13440521 its reverse (12504431), we get a palindrome (25944952).

The spelling of 13440521 in words is "thirteen million, four hundred forty thousand, five hundred twenty-one".