12801821 has 2 divisors, whose sum is σ = 12801822. Its totient is φ = 12801820.

The previous prime is 12801809. The next prime is 12801829. The reversal of 12801821 is 12810821.

It is a happy number.

12801821 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7761796 + 5040025 = 2786^2 + 2245^2 .

It is an emirp because it is prime and its reverse (12810821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 12801821 - 2¹⁰ = 12800797 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12801829) 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 as a sum of consecutive naturals, namely, 6400910 + 6400911.

It is an arithmetic number, because the mean of its divisors is an integer number (6400911).

Almost surely, 2^12801821 is an apocalyptic number.

It is an amenable number.

12801821 is a deficient number, since it is larger than the sum of its proper divisors (1).

12801821 is an equidigital number, since it uses as much as digits as its factorization.

12801821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 256, while the sum is 23.

The square root of 12801821 is about 3577.9632474356. The cubic root of 12801821 is about 233.9325115233.

The spelling of 12801821 in words is "twelve million, eight hundred one thousand, eight hundred twenty-one".