12109840 has 80 divisors (see below), whose sum is σ = 30712320. Its totient is φ = 4423680.

The previous prime is 12109817. The next prime is 12109843. The reversal of 12109840 is 4890121.

12109840 = 76² + 77² + ... + 332².

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12109843) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46992 + ... + 47248.

It is an arithmetic number, because the mean of its divisors is an integer number (383904).

Almost surely, 2^12109840 is an apocalyptic number.

12109840 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 12109840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15356160).

12109840 is an abundant number, since it is smaller than the sum of its proper divisors (18602480).

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

12109840 is a wasteful number, since it uses less digits than its factorization.

12109840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 320 (or 314 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 12109840 is about 3479.9195392997. The cubic root of 12109840 is about 229.6392580590.

Adding to 12109840 its reverse (4890121), we get a palindrome (16999961).

The spelling of 12109840 in words is "twelve million, one hundred nine thousand, eight hundred forty".