11511211516111 has 16 divisors (see below), whose sum is σ = 12257999308800. Its totient is φ = 10772217589120.

The previous prime is 11511211516069. The next prime is 11511211516117. The reversal of 11511211516111 is 11161511211511.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 11511211516111 - 2¹³ = 11511211507919 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 11511211516111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11511211516117) 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, 5970960 + ... + 7659946.

It is an arithmetic number, because the mean of its divisors is an integer number (766124956800).

Almost surely, 2^{11511211516111} is an apocalyptic number.

11511211516111 is a deficient number, since it is larger than the sum of its proper divisors (746787792689).

11511211516111 is a wasteful number, since it uses less digits than its factorization.

11511211516111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1691294.

The product of its digits is 300, while the sum is 28.

Adding to 11511211516111 its reverse (11161511211511), we get a palindrome (22672722727622).

The spelling of 11511211516111 in words is "eleven trillion, five hundred eleven billion, two hundred eleven million, five hundred sixteen thousand, one hundred eleven".