12686221 has 4 divisors (see below), whose sum is σ = 12708000. Its totient is φ = 12664444.

The previous prime is 12686213. The next prime is 12686251. The reversal of 12686221 is 12268621.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12268621 = 79 ⋅155299.

It is a cyclic number.

It is not a de Polignac number, because 12686221 - 2³ = 12686213 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12686221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12686251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9991 + ... + 11188.

It is an arithmetic number, because the mean of its divisors is an integer number (3177000).

Almost surely, 2^12686221 is an apocalyptic number.

It is an amenable number.

12686221 is a deficient number, since it is larger than the sum of its proper divisors (21779).

12686221 is an equidigital number, since it uses as much as digits as its factorization.

12686221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21778.

The product of its digits is 2304, while the sum is 28.

The square root of 12686221 is about 3561.7721712653. The cubic root of 12686221 is about 233.2262472333.

The spelling of 12686221 in words is "twelve million, six hundred eighty-six thousand, two hundred twenty-one".