11855116121 has 4 divisors (see below), whose sum is σ = 11921346000. Its totient is φ = 11788886244.

The previous prime is 11855116109. The next prime is 11855116181. The reversal of 11855116121 is 12161155811.

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 a de Polignac number, because none of the positive numbers 2^k-11855116121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11855116181) 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, 33114671 + ... + 33115028.

It is an arithmetic number, because the mean of its divisors is an integer number (2980336500).

Almost surely, 2^11855116121 is an apocalyptic number.

It is an amenable number.

11855116121 is a deficient number, since it is larger than the sum of its proper divisors (66229879).

11855116121 is an equidigital number, since it uses as much as digits as its factorization.

11855116121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66229878.

The product of its digits is 2400, while the sum is 32.

The spelling of 11855116121 in words is "eleven billion, eight hundred fifty-five million, one hundred sixteen thousand, one hundred twenty-one".