12391812 has 48 divisors (see below), whose sum is σ = 32356800. Its totient is φ = 4101120.

The previous prime is 12391811. The next prime is 12391831. The reversal of 12391812 is 21819321.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

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 (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19012 + ... + 19652.

It is an arithmetic number, because the mean of its divisors is an integer number (674100).

Almost surely, 2^12391812 is an apocalyptic number.

12391812 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12391812, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16178400).

12391812 is an abundant number, since it is smaller than the sum of its proper divisors (19964988).

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

12391812 is a wasteful number, since it uses less digits than its factorization.

12391812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 833 (or 825 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 12391812 is about 3520.2005624680. The cubic root of 12391812 is about 231.4079483877.

It can be divided in two parts, 12391 and 812, that added together give a triangular number (13203 = T₁₆₂).

The spelling of 12391812 in words is "twelve million, three hundred ninety-one thousand, eight hundred twelve".