12027821 has 4 divisors (see below), whose sum is σ = 12953052. Its totient is φ = 11102592.

The previous prime is 12027811. The next prime is 12027853. The reversal of 12027821 is 12872021.

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

It can be written as a sum of positive squares in 2 ways, for example, as 4791721 + 7236100 = 2189^2 + 2690^2 .

It is a cyclic number.

It is not a de Polignac number, because 12027821 - 2¹⁰ = 12026797 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 (12027811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 462596 + ... + 462621.

It is an arithmetic number, because the mean of its divisors is an integer number (3238263).

Almost surely, 2^12027821 is an apocalyptic number.

It is an amenable number.

12027821 is a deficient number, since it is larger than the sum of its proper divisors (925231).

12027821 is an equidigital number, since it uses as much as digits as its factorization.

12027821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 925230.

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 12027821 is about 3468.1149058242. The cubic root of 12027821 is about 229.1196402606.

Adding to 12027821 its reverse (12872021), we get a palindrome (24899842).

The spelling of 12027821 in words is "twelve million, twenty-seven thousand, eight hundred twenty-one".