12805221 has 32 divisors (see below), whose sum is σ = 21127680. Its totient is φ = 6782400.

The previous prime is 12805217. The next prime is 12805229. The reversal of 12805221 is 12250821.

It is a happy number.

It is not a de Polignac number, because 12805221 - 2² = 12805217 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12805229) 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 31 ways as a sum of consecutive naturals, for example, 7366 + ... + 8936.

It is an arithmetic number, because the mean of its divisors is an integer number (660240).

Almost surely, 2^12805221 is an apocalyptic number.

12805221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12805221 is a deficient number, since it is larger than the sum of its proper divisors (8322459).

12805221 is a wasteful number, since it uses less digits than its factorization.

12805221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1617.

The product of its (nonzero) digits is 320, while the sum is 21.

The square root of 12805221 is about 3578.4383465417. The cubic root of 12805221 is about 233.9532195183.

The spelling of 12805221 in words is "twelve million, eight hundred five thousand, two hundred twenty-one".