12806221 has 4 divisors (see below), whose sum is σ = 12863872. Its totient is φ = 12748572.

The previous prime is 12806203. The next prime is 12806249. The reversal of 12806221 is 12260821.

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 12806221 - 2¹¹ = 12804173 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12806192 and 12806201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12806201) 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, 28491 + ... + 28936.

It is an arithmetic number, because the mean of its divisors is an integer number (3215968).

Almost surely, 2^12806221 is an apocalyptic number.

It is an amenable number.

12806221 is a deficient number, since it is larger than the sum of its proper divisors (57651).

12806221 is an equidigital number, since it uses as much as digits as its factorization.

12806221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57650.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 12806221 is about 3578.5780695690. The cubic root of 12806221 is about 233.9593094075.

The spelling of 12806221 in words is "twelve million, eight hundred six thousand, two hundred twenty-one".