12185821 has 16 divisors (see below), whose sum is σ = 14031360. Its totient is φ = 10506240.

The previous prime is 12185809. The next prime is 12185843. The reversal of 12185821 is 12858121.

It is not a de Polignac number, because 12185821 - 2⁹ = 12185309 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12185821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12185891) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9405 + ... + 10621.

It is an arithmetic number, because the mean of its divisors is an integer number (876960).

Almost surely, 2^12185821 is an apocalyptic number.

It is an amenable number.

12185821 is a deficient number, since it is larger than the sum of its proper divisors (1845539).

12185821 is a wasteful number, since it uses less digits than its factorization.

12185821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1284.

The product of its digits is 1280, while the sum is 28.

The square root of 12185821 is about 3490.8195312849. The cubic root of 12185821 is about 230.1185337345.

The spelling of 12185821 in words is "twelve million, one hundred eighty-five thousand, eight hundred twenty-one".