639499284 has 36 divisors (see below), whose sum is σ = 1623241620. Its totient is φ = 212279040.

The previous prime is 639499277. The next prime is 639499297. The reversal of 639499284 is 482994936.

639499284 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 201015684 + 438483600 = 14178^2 + 20940^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a self number, because there is not a number n which added to its sum of digits gives 639499284.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28179 + ... + 45530.

It is an arithmetic number, because the mean of its divisors is an integer number (45090045).

Almost surely, 2^639499284 is an apocalyptic number.

It is an amenable number.

639499284 is an abundant number, since it is smaller than the sum of its proper divisors (983742336).

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

639499284 is a wasteful number, since it uses less digits than its factorization.

639499284 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73960 (or 73955 counting only the distinct ones).

The product of its digits is 3359232, while the sum is 54.

The square root of 639499284 is about 25288.3230760760. The cubic root of 639499284 is about 861.5490757269.

The spelling of 639499284 in words is "six hundred thirty-nine million, four hundred ninety-nine thousand, two hundred eighty-four".