6440398848 has 312 divisors, whose sum is σ = 20393624160. Its totient is φ = 1946419200.

The previous prime is 6440398829. The next prime is 6440398891. The reversal of 6440398848 is 8488930446.

It is a tau number, because it is divible by the number of its divisors (312).

It is a junction number, because it is equal to n+sod(n) for n = 6440398794 and 6440398803.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 42651573 + ... + 42651723.

It is an arithmetic number, because the mean of its divisors is an integer number (65364180).

Almost surely, 2^6440398848 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 6440398848, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10196812080).

6440398848 is an abundant number, since it is smaller than the sum of its proper divisors (13953225312).

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

6440398848 is a wasteful number, since it uses less digits than its factorization.

6440398848 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283 (or 258 counting only the distinct ones).

The product of its (nonzero) digits is 5308416, while the sum is 54.

The square root of 6440398848 is about 80252.0955988066. The cubic root of 6440398848 is about 1860.5339015362.

The spelling of 6440398848 in words is "six billion, four hundred forty million, three hundred ninety-eight thousand, eight hundred forty-eight".