6440128 has 28 divisors (see below), whose sum is σ = 13057632. Its totient is φ = 3150080.

The previous prime is 6440113. The next prime is 6440131. The reversal of 6440128 is 8210446.

It is an Ulam number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1938 + ... + 4078.

It is an arithmetic number, because the mean of its divisors is an integer number (466344).

Almost surely, 2^6440128 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6440128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6528816).

6440128 is an abundant number, since it is smaller than the sum of its proper divisors (6617504).

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

6440128 is a wasteful number, since it uses less digits than its factorization.

6440128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2200 (or 2190 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 6440128 is about 2537.7407274976. The cubic root of 6440128 is about 186.0507819873.

The spelling of 6440128 in words is "six million, four hundred forty thousand, one hundred twenty-eight".