11111100121 has 4 divisors (see below), whose sum is σ = 12121200144. Its totient is φ = 10101000100.

The previous prime is 11111100089. The next prime is 11111100137. The reversal of 11111100121 is 12100111111.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 11111100121 - 2⁵ = 11111100089 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11111100098 and 11111100107.

It is not an unprimeable number, because it can be changed into a prime (11111100151) 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, 505049995 + ... + 505050016.

It is an arithmetic number, because the mean of its divisors is an integer number (3030300036).

Almost surely, 2^11111100121 is an apocalyptic number.

11111100121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11111100121 is a deficient number, since it is larger than the sum of its proper divisors (1010100023).

11111100121 is a wasteful number, since it uses less digits than its factorization.

11111100121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1010100022.

The product of its (nonzero) digits is 2, while the sum is 10.

Adding to 11111100121 its reverse (12100111111), we get a palindrome (23211211232).

The spelling of 11111100121 in words is "eleven billion, one hundred eleven million, one hundred thousand, one hundred twenty-one".