12521 has 4 divisors (see below), whose sum is σ = 13200. Its totient is φ = 11844.

The previous prime is 12517. The next prime is 12527.

12521 is nontrivially palindromic in base 10.

12521 is digitally balanced in base 2, 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, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12521 - 2² = 12517 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 311 + ... + 348.

It is an arithmetic number, because the mean of its divisors is an integer number (3300).

2¹²⁵²¹ is an apocalyptic number.

It is an amenable number.

12521 is a deficient number, since it is larger than the sum of its proper divisors (679).

12521 is an equidigital number, since it uses as much as digits as its factorization.

12521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 678.

The product of its digits is 20, while the sum is 11.

The square root of 12521 is about 111.8972743189. The cubic root of 12521 is about 23.2209333456.

Multiplying 12521 by its sum of digits (11), we get a palindrome (137731).

The spelling of 12521 in words is "twelve thousand, five hundred twenty-one".