12155911 has 4 divisors (see below), whose sum is σ = 12166000. Its totient is φ = 12145824.

The previous prime is 12155909. The next prime is 12155917. The reversal of 12155911 is 11955121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 12155911 - 2¹ = 12155909 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 (12155917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2946 + ... + 5743.

It is an arithmetic number, because the mean of its divisors is an integer number (3041500).

Almost surely, 2^12155911 is an apocalyptic number.

12155911 is a deficient number, since it is larger than the sum of its proper divisors (10089).

12155911 is an equidigital number, since it uses as much as digits as its factorization.

12155911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10088.

The product of its digits is 450, while the sum is 25.

The square root of 12155911 is about 3486.5328049511. The cubic root of 12155911 is about 229.9301047855.

The spelling of 12155911 in words is "twelve million, one hundred fifty-five thousand, nine hundred eleven".