12001813 has 4 divisors (see below), whose sum is σ = 12707820. Its totient is φ = 11295808.

The previous prime is 12001799. The next prime is 12001819. The reversal of 12001813 is 31810021.

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 10381284 + 1620529 = 3222^2 + 1273^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12001813 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 (12001819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 352978 + ... + 353011.

It is an arithmetic number, because the mean of its divisors is an integer number (3176955).

Almost surely, 2^12001813 is an apocalyptic number.

It is an amenable number.

12001813 is a deficient number, since it is larger than the sum of its proper divisors (706007).

12001813 is an equidigital number, since it uses as much as digits as its factorization.

12001813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 706006.

The product of its (nonzero) digits is 48, while the sum is 16.

The square root of 12001813 is about 3464.3632892640. The cubic root of 12001813 is about 228.9543777463.

Adding to 12001813 its reverse (31810021), we get a palindrome (43811834).

The spelling of 12001813 in words is "twelve million, one thousand, eight hundred thirteen".