12821791 has 4 divisors (see below), whose sum is σ = 13576032. Its totient is φ = 12067552.

The previous prime is 12821761. The next prime is 12821801. The reversal of 12821791 is 19712821.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 12821791 - 2⁷ = 12821663 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12821701) 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, 377095 + ... + 377128.

It is an arithmetic number, because the mean of its divisors is an integer number (3394008).

Almost surely, 2^12821791 is an apocalyptic number.

12821791 is a deficient number, since it is larger than the sum of its proper divisors (754241).

12821791 is an equidigital number, since it uses as much as digits as its factorization.

12821791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 754240.

The product of its digits is 2016, while the sum is 31.

The square root of 12821791 is about 3580.7528538004. The cubic root of 12821791 is about 234.0540881129.

The spelling of 12821791 in words is "twelve million, eight hundred twenty-one thousand, seven hundred ninety-one".