12111840 has 144 divisors (see below), whose sum is σ = 44579808. Its totient is φ = 2976768.

The previous prime is 12111833. The next prime is 12111857. The reversal of 12111840 is 4811121.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 18397 + ... + 19043.

It is an arithmetic number, because the mean of its divisors is an integer number (309582).

Almost surely, 2^12111840 is an apocalyptic number.

12111840 is a gapful number since it is divisible by the number (10) 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 12111840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22289904).

12111840 is an abundant number, since it is smaller than the sum of its proper divisors (32467968).

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

12111840 is a wasteful number, since it uses less digits than its factorization.

12111840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 681 (or 670 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

The square root of 12111840 is about 3480.2068904018. The cubic root of 12111840 is about 229.6518993831.

Adding to 12111840 its reverse (4811121), we get a palindrome (16922961).

The spelling of 12111840 in words is "twelve million, one hundred eleven thousand, eight hundred forty".