12840400 has 60 divisors (see below), whose sum is σ = 31551552. Its totient is φ = 5019520.

The previous prime is 12840391. The next prime is 12840427. The reversal of 12840400 is 404821.

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 11 ways as a sum of consecutive naturals, for example, 18459 + ... + 19141.

Almost surely, 2^12840400 is an apocalyptic number.

12840400 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 12840400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15775776).

12840400 is an abundant number, since it is smaller than the sum of its proper divisors (18711152).

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

12840400 is a wasteful number, since it uses less digits than its factorization.

12840400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 748 (or 737 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

The square root of 12840400 is about 3583.3503875563. The cubic root of 12840400 is about 234.1672654136.

The spelling of 12840400 in words is "twelve million, eight hundred forty thousand, four hundred".