12078821 has 4 divisors (see below), whose sum is σ = 12129600. Its totient is φ = 12028044.

The previous prime is 12078791. The next prime is 12078853. The reversal of 12078821 is 12887021.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 12887021 = 7 ⋅1841003.

It is a cyclic number.

It is not a de Polignac number, because 12078821 - 2¹⁸ = 11816677 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12078881) 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, 25031 + ... + 25508.

It is an arithmetic number, because the mean of its divisors is an integer number (3032400).

Almost surely, 2^12078821 is an apocalyptic number.

It is an amenable number.

12078821 is a deficient number, since it is larger than the sum of its proper divisors (50779).

12078821 is an equidigital number, since it uses as much as digits as its factorization.

12078821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50778.

The product of its (nonzero) digits is 1792, while the sum is 29.

The square root of 12078821 is about 3475.4598256921. The cubic root of 12078821 is about 229.4430190018.

The spelling of 12078821 in words is "twelve million, seventy-eight thousand, eight hundred twenty-one".