639316728 has 48 divisors (see below), whose sum is σ = 1740585600. Its totient is φ = 211985280.

The previous prime is 639316721. The next prime is 639316729. The reversal of 639316728 is 827613936.

639316728 is a `hidden beast` number, since 639 + 3 + 1 + 6 + 7 + 2 + 8 = 666.

639316728 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639316721) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9493 + ... + 36996.

It is an arithmetic number, because the mean of its divisors is an integer number (36262200).

Almost surely, 2^639316728 is an apocalyptic number.

It is an amenable number.

639316728 is an abundant number, since it is smaller than the sum of its proper divisors (1101268872).

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

639316728 is a wasteful number, since it uses less digits than its factorization.

639316728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46692 (or 46685 counting only the distinct ones).

The product of its digits is 326592, while the sum is 45.

The square root of 639316728 is about 25284.7133264350. The cubic root of 639316728 is about 861.4670866220.

The spelling of 639316728 in words is "six hundred thirty-nine million, three hundred sixteen thousand, seven hundred twenty-eight".