12857191 has 4 divisors (see below), whose sum is σ = 12922000. Its totient is φ = 12792384.

The previous prime is 12857147. The next prime is 12857209. The reversal of 12857191 is 19175821.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19175821 = 7 ⋅2739403.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12857191 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 (12857791) 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, 32106 + ... + 32503.

It is an arithmetic number, because the mean of its divisors is an integer number (3230500).

Almost surely, 2^12857191 is an apocalyptic number.

12857191 is a deficient number, since it is larger than the sum of its proper divisors (64809).

12857191 is an equidigital number, since it uses as much as digits as its factorization.

12857191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64808.

The product of its digits is 5040, while the sum is 34.

The square root of 12857191 is about 3585.6925411976. The cubic root of 12857191 is about 234.2692920878.

The spelling of 12857191 in words is "twelve million, eight hundred fifty-seven thousand, one hundred ninety-one".