12840440 has 64 divisors (see below), whose sum is σ = 31959360. Its totient is φ = 4618240.

The previous prime is 12840427. The next prime is 12840461. The reversal of 12840440 is 4404821.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15230 + ... + 16050.

It is an arithmetic number, because the mean of its divisors is an integer number (499365).

Almost surely, 2^12840440 is an apocalyptic number.

12840440 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 12840440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15979680).

12840440 is an abundant number, since it is smaller than the sum of its proper divisors (19118920).

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

12840440 is a wasteful number, since it uses less digits than its factorization.

12840440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 872 (or 868 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 23.

The square root of 12840440 is about 3583.3559689208. The cubic root of 12840440 is about 234.1675085701.

The spelling of 12840440 in words is "twelve million, eight hundred forty thousand, four hundred forty".