28643408640 has 864 divisors, whose sum is σ = 126270144000. Its totient is φ = 5942845440.

The previous prime is 28643408627. The next prime is 28643408641. The reversal of 28643408640 is 4680434682.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (28643408641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 43464631 + ... + 43465289.

It is an arithmetic number, because the mean of its divisors is an integer number (146146000).

Almost surely, 2^28643408640 is an apocalyptic number.

28643408640 is a gapful number since it is divisible by the number (20) 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 28643408640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (63135072000).

28643408640 is an abundant number, since it is smaller than the sum of its proper divisors (97626735360).

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

28643408640 is a wasteful number, since it uses less digits than its factorization.

28643408640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 718 (or 687 counting only the distinct ones).

The product of its (nonzero) digits is 884736, while the sum is 45.

The spelling of 28643408640 in words is "twenty-eight billion, six hundred forty-three million, four hundred eight thousand, six hundred forty".