12811184836561 has 4 divisors (see below), whose sum is σ = 13564783944612. Its totient is φ = 12057585728512.

The previous prime is 12811184836559. The next prime is 12811184836573. The reversal of 12811184836561 is 16563848111821.

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 9688471742161 + 3122713094400 = 3112631^2 + 1767120^2 .

It is not a de Polignac number, because 12811184836561 - 2¹ = 12811184836559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12811184836511) 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, 376799554000 + ... + 376799554033.

It is an arithmetic number, because the mean of its divisors is an integer number (3391195986153).

Almost surely, 2^{12811184836561} is an apocalyptic number.

It is an amenable number.

12811184836561 is a deficient number, since it is larger than the sum of its proper divisors (753599108051).

12811184836561 is an equidigital number, since it uses as much as digits as its factorization.

12811184836561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 753599108050.

The product of its digits is 2211840, while the sum is 55.

The spelling of 12811184836561 in words is "twelve trillion, eight hundred eleven billion, one hundred eighty-four million, eight hundred thirty-six thousand, five hundred sixty-one".