13111041551561 has 4 divisors (see below), whose sum is σ = 13127011152324. Its totient is φ = 13095071950800.

The previous prime is 13111041551549. The next prime is 13111041551563. The reversal of 13111041551561 is 16515514011131.

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 7530962947600 + 5580078603961 = 2744260^2 + 2362219^2 .

It is a cyclic number.

It is not a de Polignac number, because 13111041551561 - 2⁶ = 13111041551497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13111041551563) 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, 7984799150 + ... + 7984800791.

It is an arithmetic number, because the mean of its divisors is an integer number (3281752788081).

Almost surely, 2^{13111041551561} is an apocalyptic number.

It is an amenable number.

13111041551561 is a deficient number, since it is larger than the sum of its proper divisors (15969600763).

13111041551561 is an equidigital number, since it uses as much as digits as its factorization.

13111041551561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15969600762.

The product of its (nonzero) digits is 9000, while the sum is 35.

Adding to 13111041551561 its reverse (16515514011131), we get a palindrome (29626555562692).

The spelling of 13111041551561 in words is "thirteen trillion, one hundred eleven billion, forty-one million, five hundred fifty-one thousand, five hundred sixty-one".