12857309 has 4 divisors (see below), whose sum is σ = 12874716. Its totient is φ = 12839904.

The previous prime is 12857297. The next prime is 12857333. The reversal of 12857309 is 90375821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90375821 = 2503 ⋅36107.

It can be written as a sum of positive squares in 2 ways, for example, as 1276900 + 11580409 = 1130^2 + 3403^2 .

It is a cyclic number.

It is not a de Polignac number, because 12857309 - 2¹⁶ = 12791773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12857209) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7544 + ... + 9089.

It is an arithmetic number, because the mean of its divisors is an integer number (3218679).

Almost surely, 2^12857309 is an apocalyptic number.

It is an amenable number.

12857309 is a deficient number, since it is larger than the sum of its proper divisors (17407).

12857309 is an equidigital number, since it uses as much as digits as its factorization.

12857309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17406.

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 12857309 is about 3585.7089954429. The cubic root of 12857309 is about 234.2700087734.

The spelling of 12857309 in words is "twelve million, eight hundred fifty-seven thousand, three hundred nine".