6440928 has 72 divisors (see below), whose sum is σ = 18354168. Its totient is φ = 1976832.

The previous prime is 6440893. The next prime is 6440933. The reversal of 6440928 is 8290446.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16026 + ... + 16422.

It is an arithmetic number, because the mean of its divisors is an integer number (254919).

Almost surely, 2^6440928 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 6440928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9177084).

6440928 is an abundant number, since it is smaller than the sum of its proper divisors (11913240).

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

6440928 is a wasteful number, since it uses less digits than its factorization.

6440928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 436 (or 415 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 6440928 is about 2537.8983431178. The cubic root of 6440928 is about 186.0584854813.

The spelling of 6440928 in words is "six million, four hundred forty thousand, nine hundred twenty-eight".