13521021 has 16 divisors (see below), whose sum is σ = 18973248. Its totient is φ = 8553600.

The previous prime is 13520999. The next prime is 13521023. The reversal of 13521021 is 12012531.

It is not a de Polignac number, because 13521021 - 2⁶ = 13520957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13521023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3066 + ... + 6036.

It is an arithmetic number, because the mean of its divisors is an integer number (1185828).

Almost surely, 2^13521021 is an apocalyptic number.

It is an amenable number.

13521021 is a deficient number, since it is larger than the sum of its proper divisors (5452227).

13521021 is a wasteful number, since it uses less digits than its factorization.

13521021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3052.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 13521021 is about 3677.0940972458. The cubic root of 13521021 is about 238.2336816947.

Adding to 13521021 its reverse (12012531), we get a palindrome (25533552).

The spelling of 13521021 in words is "thirteen million, five hundred twenty-one thousand, twenty-one".