12711521 has 4 divisors (see below), whose sum is σ = 12785172. Its totient is φ = 12637872.

The previous prime is 12711509. The next prime is 12711527. The reversal of 12711521 is 12511721.

It is a happy number.

12711521 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.

It can be written as a sum of positive squares in 2 ways, for example, as 12327121 + 384400 = 3511^2 + 620^2 .

It is a cyclic number.

It is not a de Polignac number, because 12711521 - 2¹⁸ = 12449377 is a prime.

It is a super-2 number, since 2×12711521² = 323165532266882, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 12711493 and 12711502.

It is not an unprimeable number, because it can be changed into a prime (12711527) 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, 36566 + ... + 36911.

It is an arithmetic number, because the mean of its divisors is an integer number (3196293).

Almost surely, 2^12711521 is an apocalyptic number.

It is an amenable number.

12711521 is a deficient number, since it is larger than the sum of its proper divisors (73651).

12711521 is an equidigital number, since it uses as much as digits as its factorization.

12711521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73650.

The product of its digits is 140, while the sum is 20.

The square root of 12711521 is about 3565.3220050929. The cubic root of 12711521 is about 233.3811845172.

The spelling of 12711521 in words is "twelve million, seven hundred eleven thousand, five hundred twenty-one".