12821993 has 4 divisors (see below), whose sum is σ = 12829908. Its totient is φ = 12814080.

The previous prime is 12821989. The next prime is 12822001. The reversal of 12821993 is 39912821.

12821993 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 12201049 + 620944 = 3493^2 + 788^2 .

It is a cyclic number.

It is not a de Polignac number, because 12821993 - 2² = 12821989 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12821933) 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, 548 + ... + 5093.

It is an arithmetic number, because the mean of its divisors is an integer number (3207477).

Almost surely, 2^12821993 is an apocalyptic number.

It is an amenable number.

12821993 is a deficient number, since it is larger than the sum of its proper divisors (7915).

12821993 is an equidigital number, since it uses as much as digits as its factorization.

12821993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7914.

The product of its digits is 7776, while the sum is 35.

The square root of 12821993 is about 3580.7810600482. The cubic root of 12821993 is about 234.0553172359.

The spelling of 12821993 in words is "twelve million, eight hundred twenty-one thousand, nine hundred ninety-three".