6444240 has 80 divisors (see below), whose sum is σ = 21802176. Its totient is φ = 1561600.

The previous prime is 6444233. The next prime is 6444259. The reversal of 6444240 is 424446.

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

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 6444240.

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, 1420 + ... + 3860.

Almost surely, 2^6444240 is an apocalyptic number.

6444240 is a gapful number since it is divisible by the number (60) 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 6444240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10901088).

6444240 is an abundant number, since it is smaller than the sum of its proper divisors (15357936).

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

6444240 is a wasteful number, since it uses less digits than its factorization.

6444240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2468 (or 2462 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 24.

The square root of 6444240 is about 2538.5507676625. The cubic root of 6444240 is about 186.0903711615.

Adding to 6444240 its reverse (424446), we get a palindrome (6868686).

It can be divided in two parts, 644 and 4240, that added together give a palindrome (4884).

The spelling of 6444240 in words is "six million, four hundred forty-four thousand, two hundred forty".