640489824 has 288 divisors, whose sum is σ = 2154690720. Its totient is φ = 178569216.

The previous prime is 640489819. The next prime is 640489873. The reversal of 640489824 is 428984046.

It is a tau number, because it is divible by the number of its divisors (288).

It is a self number, because there is not a number n which added to its sum of digits gives 640489824.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1845619 + ... + 1845965.

It is an arithmetic number, because the mean of its divisors is an integer number (7481565).

Almost surely, 2^640489824 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 640489824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1077345360).

640489824 is an abundant number, since it is smaller than the sum of its proper divisors (1514200896).

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

640489824 is a wasteful number, since it uses less digits than its factorization.

640489824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 422 (or 411 counting only the distinct ones).

The product of its (nonzero) digits is 442368, while the sum is 45.

The square root of 640489824 is about 25307.9004265466. The cubic root of 640489824 is about 861.9936728271.

The spelling of 640489824 in words is "six hundred forty million, four hundred eighty-nine thousand, eight hundred twenty-four".