12115881 has 24 divisors (see below), whose sum is σ = 18425160. Its totient is φ = 7660800.

The previous prime is 12115867. The next prime is 12115889. The reversal of 12115881 is 18851121.

It can be written as a sum of positive squares in 4 ways, for example, as 826281 + 11289600 = 909^2 + 3360^2 .

It is not a de Polignac number, because 12115881 - 2¹⁰ = 12114857 is a prime.

It is a super-2 number, since 2×12115881² = 293589144812322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (12115889) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15541 + ... + 16301.

It is an arithmetic number, because the mean of its divisors is an integer number (767715).

Almost surely, 2^12115881 is an apocalyptic number.

It is an amenable number.

12115881 is a deficient number, since it is larger than the sum of its proper divisors (6309279).

12115881 is a wasteful number, since it uses less digits than its factorization.

12115881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 857 (or 854 counting only the distinct ones).

The product of its digits is 640, while the sum is 27.

The square root of 12115881 is about 3480.7874109172. The cubic root of 12115881 is about 229.6774369324.

It can be divided in two parts, 12115 and 881, that added together give a square (12996 = 114²).

The spelling of 12115881 in words is "twelve million, one hundred fifteen thousand, eight hundred eighty-one".