12857321 has 8 divisors (see below), whose sum is σ = 13665960. Its totient is φ = 12096384.

The previous prime is 12857297. The next prime is 12857333. The reversal of 12857321 is 12375821.

It can be written as a sum of positive squares in 4 ways, for example, as 6071296 + 6786025 = 2464^2 + 2605^2 .

It is a de Polignac number, because none of the positive numbers 2^k-12857321 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12857381) 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 7 ways as a sum of consecutive naturals, for example, 3605 + ... + 6221.

It is an arithmetic number, because the mean of its divisors is an integer number (1708245).

Almost surely, 2^12857321 is an apocalyptic number.

It is an amenable number.

12857321 is a deficient number, since it is larger than the sum of its proper divisors (808639).

12857321 is an frugal number, since it uses more digits than its factorization.

12857321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2668 (or 2634 counting only the distinct ones).

The product of its digits is 3360, while the sum is 29.

The square root of 12857321 is about 3585.7106687517. The cubic root of 12857321 is about 234.2700816564.

The spelling of 12857321 in words is "twelve million, eight hundred fifty-seven thousand, three hundred twenty-one".