6399655280 has 40 divisors (see below), whose sum is σ = 14893578000. Its totient is φ = 2557388288.

The previous prime is 6399655277. The next prime is 6399655291. The reversal of 6399655280 is 825569936.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45791 + ... + 122049.

It is an arithmetic number, because the mean of its divisors is an integer number (372339450).

Almost surely, 2^6399655280 is an apocalyptic number.

It is an amenable number.

6399655280 is an abundant number, since it is smaller than the sum of its proper divisors (8493922720).

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

6399655280 is a wasteful number, since it uses less digits than its factorization.

6399655280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77321 (or 77315 counting only the distinct ones).

The product of its (nonzero) digits is 3499200, while the sum is 53.

The square root of 6399655280 is about 79997.8454709875. The cubic root of 6399655280 is about 1856.6021985028.

The spelling of 6399655280 in words is "six billion, three hundred ninety-nine million, six hundred fifty-five thousand, two hundred eighty".