13406521 has 4 divisors (see below), whose sum is σ = 13431844. Its totient is φ = 13381200.

The previous prime is 13406513. The next prime is 13406527. The reversal of 13406521 is 12560431.

13406521 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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 5112121 + 8294400 = 2261^2 + 2880^2 .

It is a cyclic number.

It is not a de Polignac number, because 13406521 - 2³ = 13406513 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13406492 and 13406501.

It is not an unprimeable number, because it can be changed into a prime (13406527) 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 3 ways as a sum of consecutive naturals, for example, 11850 + ... + 12931.

It is an arithmetic number, because the mean of its divisors is an integer number (3357961).

Almost surely, 2^13406521 is an apocalyptic number.

It is an amenable number.

13406521 is a deficient number, since it is larger than the sum of its proper divisors (25323).

13406521 is an equidigital number, since it uses as much as digits as its factorization.

13406521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25322.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 13406521 is about 3661.4916359320. The cubic root of 13406521 is about 237.5592967361.

Adding to 13406521 its reverse (12560431), we get a palindrome (25966952).

The spelling of 13406521 in words is "thirteen million, four hundred six thousand, five hundred twenty-one".