12185001821 has 8 divisors (see below), whose sum is σ = 12904851960. Its totient is φ = 11465494528.

The previous prime is 12185001781. The next prime is 12185001823. The reversal of 12185001821 is 12810058121.

It can be written as a sum of positive squares in 4 ways, for example, as 7870351225 + 4314650596 = 88715^2 + 65686^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12185001821 - 2⁶ = 12185001757 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 (12185001823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10646 + ... + 156471.

It is an arithmetic number, because the mean of its divisors is an integer number (1613106495).

Almost surely, 2^12185001821 is an apocalyptic number.

It is an amenable number.

12185001821 is a deficient number, since it is larger than the sum of its proper divisors (719850139).

12185001821 is a wasteful number, since it uses less digits than its factorization.

12185001821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171423.

The product of its (nonzero) digits is 1280, while the sum is 29.

Adding to 12185001821 its reverse (12810058121), we get a palindrome (24995059942).

The spelling of 12185001821 in words is "twelve billion, one hundred eighty-five million, one thousand, eight hundred twenty-one".