6440868028 has 24 divisors (see below), whose sum is σ = 12884088672. Its totient is φ = 2759867904.

The previous prime is 6440868019. The next prime is 6440868041. The reversal of 6440868028 is 8208680446.

It is a super-2 number, since 2×6440868028² = 82969561908225217568, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 163476 + ... + 199012.

It is an arithmetic number, because the mean of its divisors is an integer number (536837028).

Almost surely, 2^6440868028 is an apocalyptic number.

It is an amenable number.

6440868028 is an abundant number, since it is smaller than the sum of its proper divisors (6443220644).

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

6440868028 is a wasteful number, since it uses less digits than its factorization.

6440868028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42021 (or 42019 counting only the distinct ones).

The product of its (nonzero) digits is 589824, while the sum is 46.

The square root of 6440868028 is about 80255.0187091125. The cubic root of 6440868028 is about 1860.5790801098.

The spelling of 6440868028 in words is "six billion, four hundred forty million, eight hundred sixty-eight thousand, twenty-eight".