12391686 has 36 divisors (see below), whose sum is σ = 28350972. Its totient is φ = 3911112.

The previous prime is 12391679. The next prime is 12391699. The reversal of 12391686 is 68619321.

It is a self number, because there is not a number n which added to its sum of digits gives 12391686.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 5545 + ... + 7451.

It is an arithmetic number, because the mean of its divisors is an integer number (787527).

Almost surely, 2^12391686 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12391686, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14175486).

12391686 is an abundant number, since it is smaller than the sum of its proper divisors (15959286).

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

12391686 is a wasteful number, since it uses less digits than its factorization.

12391686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1953 (or 1931 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 12391686 is about 3520.1826657149. The cubic root of 12391686 is about 231.4071640660.

It can be divided in two parts, 123 and 91686, that added together give a square (91809 = 303²).

The spelling of 12391686 in words is "twelve million, three hundred ninety-one thousand, six hundred eighty-six".