6440878080 has 640 divisors, whose sum is σ = 28185696000. Its totient is φ = 1358954496.

The previous prime is 6440878079. The next prime is 6440878097. The reversal of 6440878080 is 808780446.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a zygodrome in base 4.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 495452154 + ... + 495452166.

It is an arithmetic number, because the mean of its divisors is an integer number (44040150).

Almost surely, 2^6440878080 is an apocalyptic number.

6440878080 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 6440878080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14092848000).

6440878080 is an abundant number, since it is smaller than the sum of its proper divisors (21744817920).

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

6440878080 is an frugal number, since it uses more digits than its factorization.

6440878080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72 (or 30 counting only the distinct ones).

The product of its (nonzero) digits is 344064, while the sum is 45.

The square root of 6440878080 is about 80255.0813344551. The cubic root of 6440878080 is about 1860.5800480192.

The spelling of 6440878080 in words is "six billion, four hundred forty million, eight hundred seventy-eight thousand, eighty".