12856991 has 8 divisors (see below), whose sum is σ = 15006720. Its totient is φ = 10785528.

The previous prime is 12856969. The next prime is 12856999. The reversal of 12856991 is 19965821.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12856991 - 2¹⁰ = 12855967 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 (12856999) 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, 19211 + ... + 19868.

It is an arithmetic number, because the mean of its divisors is an integer number (1875840).

Almost surely, 2^12856991 is an apocalyptic number.

12856991 is a deficient number, since it is larger than the sum of its proper divisors (2149729).

12856991 is an equidigital number, since it uses as much as digits as its factorization.

12856991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39133.

The product of its digits is 38880, while the sum is 41.

The square root of 12856991 is about 3585.6646524738. The cubic root of 12856991 is about 234.2680773564.

The spelling of 12856991 in words is "twelve million, eight hundred fifty-six thousand, nine hundred ninety-one".