639304189 has 4 divisors (see below), whose sum is σ = 639360160. Its totient is φ = 639248220.

The previous prime is 639304187. The next prime is 639304213. The reversal of 639304189 is 981403936.

639304189 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 639304189 - 2¹ = 639304187 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639304181) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3999 + ... + 35980.

It is an arithmetic number, because the mean of its divisors is an integer number (159840040).

Almost surely, 2^639304189 is an apocalyptic number.

It is an amenable number.

639304189 is a deficient number, since it is larger than the sum of its proper divisors (55971).

639304189 is a wasteful number, since it uses less digits than its factorization.

639304189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55970.

The product of its (nonzero) digits is 139968, while the sum is 43.

The square root of 639304189 is about 25284.4653690759. The cubic root of 639304189 is about 861.4614545642.

The spelling of 639304189 in words is "six hundred thirty-nine million, three hundred four thousand, one hundred eighty-nine".