6440936320 has 512 divisors, whose sum is σ = 20186208000. Its totient is φ = 1950842880.

The previous prime is 6440936317. The next prime is 6440936321. The reversal of 6440936320 is 236390446.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a self number, because there is not a number n which added to its sum of digits gives 6440936320.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6440936321) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 105589090 + ... + 105589150.

Almost surely, 2^6440936320 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 6440936320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10093104000).

6440936320 is an abundant number, since it is smaller than the sum of its proper divisors (13745271680).

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

6440936320 is a wasteful number, since it uses less digits than its factorization.

6440936320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151 (or 125 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 37.

The square root of 6440936320 is about 80255.4441767037. Note that the first 3 decimals coincide. The cubic root of 6440936320 is about 1860.5856559428.

The spelling of 6440936320 in words is "six billion, four hundred forty million, nine hundred thirty-six thousand, three hundred twenty".