12391881 has 8 divisors (see below), whose sum is σ = 16925664. Its totient is φ = 8059680.

The previous prime is 12391867. The next prime is 12391913. The reversal of 12391881 is 18819321.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 12391881 - 2⁹ = 12391369 is a prime.

It is a super-2 number, since 2×12391881² = 307117429436322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (12391811) 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 7 ways as a sum of consecutive naturals, for example, 50251 + ... + 50496.

It is an arithmetic number, because the mean of its divisors is an integer number (2115708).

Almost surely, 2^12391881 is an apocalyptic number.

It is an amenable number.

12391881 is a deficient number, since it is larger than the sum of its proper divisors (4533783).

12391881 is a wasteful number, since it uses less digits than its factorization.

12391881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100791.

The product of its digits is 3456, while the sum is 33.

The square root of 12391881 is about 3520.2103630323. The cubic root of 12391881 is about 231.4083778949.

The spelling of 12391881 in words is "twelve million, three hundred ninety-one thousand, eight hundred eighty-one".