12286721 has 4 divisors (see below), whose sum is σ = 12293892. Its totient is φ = 12279552.

The previous prime is 12286709. The next prime is 12286723. The reversal of 12286721 is 12768221.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 1795600 + 10491121 = 1340^2 + 3239^2 .

It is a cyclic number.

It is not a de Polignac number, because 12286721 - 2¹⁸ = 12024577 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (12286723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 665 + ... + 5001.

It is an arithmetic number, because the mean of its divisors is an integer number (3073473).

Almost surely, 2^12286721 is an apocalyptic number.

It is an amenable number.

12286721 is a deficient number, since it is larger than the sum of its proper divisors (7171).

12286721 is an equidigital number, since it uses as much as digits as its factorization.

12286721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7170.

The product of its digits is 2688, while the sum is 29.

The square root of 12286721 is about 3505.2419317360. The cubic root of 12286721 is about 230.7519247335.

The spelling of 12286721 in words is "twelve million, two hundred eighty-six thousand, seven hundred twenty-one".