6399120000 has 640 divisors, whose sum is σ = 26231103360. Its totient is φ = 1345536000.

The previous prime is 6399119981. The next prime is 6399120011. The reversal of 6399120000 is 219936.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a self number, because there is not a number n which added to its sum of digits gives 6399120000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 21839854 + ... + 21840146.

It is an arithmetic number, because the mean of its divisors is an integer number (40986099).

Almost surely, 2^6399120000 is an apocalyptic number.

6399120000 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 6399120000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13115551680).

6399120000 is an abundant number, since it is smaller than the sum of its proper divisors (19831983360).

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

6399120000 is a wasteful number, since it uses less digits than its factorization.

6399120000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350 (or 323 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 30.

The square root of 6399120000 is about 79994.4998109245. The cubic root of 6399120000 is about 1856.5504337493.

Adding to 6399120000 its reverse (219936), we get a palindrome (6399339936).

The spelling of 6399120000 in words is "six billion, three hundred ninety-nine million, one hundred twenty thousand".