12391986 has 16 divisors (see below), whose sum is σ = 25861824. Its totient is φ = 3951024.

The previous prime is 12391937. The next prime is 12391987. The reversal of 12391986 is 68919321.

12391986 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×12391986² = 307122634048392, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (12391987) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44761 + ... + 45036.

It is an arithmetic number, because the mean of its divisors is an integer number (1616364).

Almost surely, 2^12391986 is an apocalyptic number.

12391986 is an abundant number, since it is smaller than the sum of its proper divisors (13469838).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

12391986 is a wasteful number, since it uses less digits than its factorization.

12391986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89825.

The product of its digits is 23328, while the sum is 39.

The square root of 12391986 is about 3520.2252768821. The cubic root of 12391986 is about 231.4090314898.

The spelling of 12391986 in words is "twelve million, three hundred ninety-one thousand, nine hundred eighty-six".