11111111211111 has 16 divisors (see below), whose sum is σ = 15538943345664. Its totient is φ = 7053862433184.

The previous prime is 11111111211059. The next prime is 11111111211113. The reversal of 11111111211111 is 11111211111111.

It is not a de Polignac number, because 11111111211111 - 2⁶ = 11111111211047 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11111111211113) 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, 1064889475 + ... + 1064899908.

It is an arithmetic number, because the mean of its divisors is an integer number (971183959104).

Almost surely, 2^{11111111211111} is an apocalyptic number.

11111111211111 is a deficient number, since it is larger than the sum of its proper divisors (4427832134553).

11111111211111 is a wasteful number, since it uses less digits than its factorization.

11111111211111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2129789470.

The product of its digits is 2, while the sum is 15.

Adding to 11111111211111 its reverse (11111211111111), we get a palindrome (22222322322222).

It can be divided in two parts, 111 and 11111211111, that multiplied together give a palindrome (1233344433321).

The spelling of 11111111211111 in words is "eleven trillion, one hundred eleven billion, one hundred eleven million, two hundred eleven thousand, one hundred eleven".