6440375280 has 80 divisors (see below), whose sum is σ = 21015976320. Its totient is φ = 1627041024.

The previous prime is 6440375269. The next prime is 6440375311. The reversal of 6440375280 is 825730446.

It is a happy number.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 701622 + ... + 710741.

It is an arithmetic number, because the mean of its divisors is an integer number (262699704).

Almost surely, 2^6440375280 is an apocalyptic number.

6440375280 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6440375280 is an abundant number, since it is smaller than the sum of its proper divisors (14575601040).

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

6440375280 is a wasteful number, since it uses less digits than its factorization.

6440375280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1412398 (or 1412392 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 39.

The square root of 6440375280 is about 80251.9487613852. The cubic root of 6440375280 is about 1860.5316320538.

The spelling of 6440375280 in words is "six billion, four hundred forty million, three hundred seventy-five thousand, two hundred eighty".