6400987880 has 256 divisors, whose sum is σ = 17915904000. Its totient is φ = 2011161600.

The previous prime is 6400987829. The next prime is 6400987903. The reversal of 6400987880 is 887890046.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 14851265 + ... + 14851695.

It is an arithmetic number, because the mean of its divisors is an integer number (69984000).

Almost surely, 2^6400987880 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 6400987880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8957952000).

6400987880 is an abundant number, since it is smaller than the sum of its proper divisors (11514916120).

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

6400987880 is a wasteful number, since it uses less digits than its factorization.

6400987880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 568 (or 564 counting only the distinct ones).

The product of its (nonzero) digits is 774144, while the sum is 50.

The square root of 6400987880 is about 80006.1740117599. The cubic root of 6400987880 is about 1856.7310562966.

The spelling of 6400987880 in words is "six billion, four hundred million, nine hundred eighty-seven thousand, eight hundred eighty".