11122121111 has 4 divisors (see below), whose sum is σ = 11232241224. Its totient is φ = 11012001000.

The previous prime is 11122121107. The next prime is 11122121113. The reversal of 11122121111 is 11112122111.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11112122111 = 101 ⋅110021011.

It is a cyclic number.

It is not a de Polignac number, because 11122121111 - 2² = 11122121107 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 (11122121113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55059905 + ... + 55060106.

It is an arithmetic number, because the mean of its divisors is an integer number (2808060306).

Almost surely, 2^11122121111 is an apocalyptic number.

11122121111 is a deficient number, since it is larger than the sum of its proper divisors (110120113).

11122121111 is a wasteful number, since it uses less digits than its factorization.

11122121111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110120112.

The product of its digits is 8, while the sum is 14.

Adding to 11122121111 its reverse (11112122111), we get a palindrome (22234243222).

The spelling of 11122121111 in words is "eleven billion, one hundred twenty-two million, one hundred twenty-one thousand, one hundred eleven".