6408444840 has 128 divisors (see below), whose sum is σ = 22112213760. Its totient is φ = 1455427584.

The previous prime is 6408444839. The next prime is 6408444871. The reversal of 6408444840 is 484448046.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 6408444792 and 6408444801.

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, 107584 + ... + 156176.

It is an arithmetic number, because the mean of its divisors is an integer number (172751670).

Almost surely, 2^6408444840 is an apocalyptic number.

6408444840 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 6408444840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11056106880).

6408444840 is an abundant number, since it is smaller than the sum of its proper divisors (15703768920).

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

6408444840 is a wasteful number, since it uses less digits than its factorization.

6408444840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48771 (or 48767 counting only the distinct ones).

The product of its (nonzero) digits is 393216, while the sum is 42.

The square root of 6408444840 is about 80052.7628505100. The cubic root of 6408444840 is about 1857.4517885958.

The spelling of 6408444840 in words is "six billion, four hundred eight million, four hundred forty-four thousand, eight hundred forty".