11111212201111 has 16 divisors (see below), whose sum is σ = 12693348373248. Its totient is φ = 9627539521600.

The previous prime is 11111212201073. The next prime is 11111212201123. The reversal of 11111212201111 is 11110221211111.

It is not a de Polignac number, because 11111212201111 - 2²⁹ = 11110675330199 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 (11111212205111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 78074521 + ... + 78216706.

It is an arithmetic number, because the mean of its divisors is an integer number (793334273328).

Almost surely, 2^{11111212201111} is an apocalyptic number.

11111212201111 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

11111212201111 is a deficient number, since it is larger than the sum of its proper divisors (1582136172137).

11111212201111 is a wasteful number, since it uses less digits than its factorization.

11111212201111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156291542.

The product of its (nonzero) digits is 8, while the sum is 16.

Adding to 11111212201111 its reverse (11110221211111), we get a palindrome (22221433412222).

The spelling of 11111212201111 in words is "eleven trillion, one hundred eleven billion, two hundred twelve million, two hundred one thousand, one hundred eleven".