12440400 has 120 divisors (see below), whose sum is σ = 45574464. Its totient is φ = 2841600.

The previous prime is 12440381. The next prime is 12440411. The reversal of 12440400 is 404421.

12440400 = 413² + 414² + ... + 475².

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 12440400.

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, 7660 + ... + 9140.

Almost surely, 2^12440400 is an apocalyptic number.

12440400 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 12440400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22787232).

12440400 is an abundant number, since it is smaller than the sum of its proper divisors (33134064).

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

12440400 is a wasteful number, since it uses less digits than its factorization.

12440400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1509 (or 1498 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 15.

The square root of 12440400 is about 3527.0951220516. The cubic root of 12440400 is about 231.7100023021.

Adding to 12440400 its reverse (404421), we get a palindrome (12844821).

The spelling of 12440400 in words is "twelve million, four hundred forty thousand, four hundred".