6444500640 has 192 divisors, whose sum is σ = 21914323200. Its totient is φ = 1587052544.

The previous prime is 6444500609. The next prime is 6444500681. The reversal of 6444500640 is 460054446.

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, 310096 + ... + 330224.

It is an arithmetic number, because the mean of its divisors is an integer number (114137100).

Almost surely, 2^6444500640 is an apocalyptic number.

6444500640 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 6444500640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10957161600).

6444500640 is an abundant number, since it is smaller than the sum of its proper divisors (15469822560).

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

6444500640 is a wasteful number, since it uses less digits than its factorization.

6444500640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20199 (or 20191 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 33.

The square root of 6444500640 is about 80277.6472002014. The cubic root of 6444500640 is about 1860.9287996211.

The spelling of 6444500640 in words is "six billion, four hundred forty-four million, five hundred thousand, six hundred forty".