13123521 has 6 divisors (see below), whose sum is σ = 18956210. Its totient is φ = 8749008.

The previous prime is 13123463. The next prime is 13123529. The reversal of 13123521 is 12532131.

13123521 is a `hidden beast` number, since 1 + 312 + 352 + 1 = 666.

13123521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 7535025 + 5588496 = 2745^2 + 2364^2 .

It is not a de Polignac number, because 13123521 - 2⁷ = 13123393 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13123494 and 13123503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13123529) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 729076 + ... + 729093.

Almost surely, 2^13123521 is an apocalyptic number.

It is an amenable number.

13123521 is a deficient number, since it is larger than the sum of its proper divisors (5832689).

13123521 is a wasteful number, since it uses less digits than its factorization.

13123521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1458175 (or 1458172 counting only the distinct ones).

The product of its digits is 180, while the sum is 18.

The square root of 13123521 is about 3622.6400594042. The cubic root of 13123521 is about 235.8758384044.

Adding to 13123521 its reverse (12532131), we get a palindrome (25655652).

The spelling of 13123521 in words is "thirteen million, one hundred twenty-three thousand, five hundred twenty-one".