13530521 has 4 divisors (see below), whose sum is σ = 14326452. Its totient is φ = 12734592.

The previous prime is 13530499. The next prime is 13530523. The reversal of 13530521 is 12503531.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12503531 = 127 ⋅98453.

It can be written as a sum of positive squares in 2 ways, for example, as 9486400 + 4044121 = 3080^2 + 2011^2 .

It is a cyclic number.

It is not a de Polignac number, because 13530521 - 2⁶ = 13530457 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 13530493 and 13530502.

It is not an unprimeable number, because it can be changed into a prime (13530523) 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, 397940 + ... + 397973.

It is an arithmetic number, because the mean of its divisors is an integer number (3581613).

Almost surely, 2^13530521 is an apocalyptic number.

It is an amenable number.

13530521 is a deficient number, since it is larger than the sum of its proper divisors (795931).

13530521 is an equidigital number, since it uses as much as digits as its factorization.

13530521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 795930.

The product of its (nonzero) digits is 450, while the sum is 20.

The square root of 13530521 is about 3678.3856513422. The cubic root of 13530521 is about 238.2894637280.

The spelling of 13530521 in words is "thirteen million, five hundred thirty thousand, five hundred twenty-one".