12857905 has 4 divisors (see below), whose sum is σ = 15429492. Its totient is φ = 10286320.

The previous prime is 12857893. The next prime is 12857909. The reversal of 12857905 is 50975821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50975821 = 13 ⋅3921217.

It can be written as a sum of positive squares in 2 ways, for example, as 9144576 + 3713329 = 3024^2 + 1927^2 .

It is not a de Polignac number, because 12857905 - 2¹³ = 12849713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12857909) 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, 1285786 + ... + 1285795.

It is an arithmetic number, because the mean of its divisors is an integer number (3857373).

Almost surely, 2^12857905 is an apocalyptic number.

It is an amenable number.

12857905 is a deficient number, since it is larger than the sum of its proper divisors (2571587).

12857905 is an equidigital number, since it uses as much as digits as its factorization.

12857905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2571586.

The product of its (nonzero) digits is 25200, while the sum is 37.

The square root of 12857905 is about 3585.7921021721. The cubic root of 12857905 is about 234.2736285762.

The spelling of 12857905 in words is "twelve million, eight hundred fifty-seven thousand, nine hundred five".