639403885 has 8 divisors (see below), whose sum is σ = 771180696. Its totient is φ = 508925760.

The previous prime is 639403879. The next prime is 639403901. The reversal of 639403885 is 588304936.

639403885 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 4 ways, for example, as 48038761 + 591365124 = 6931^2 + 24318^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 639403885 - 2¹³ = 639395693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 323586 + ... + 325555.

It is an arithmetic number, because the mean of its divisors is an integer number (96397587).

Almost surely, 2^639403885 is an apocalyptic number.

It is an amenable number.

639403885 is a deficient number, since it is larger than the sum of its proper divisors (131776811).

639403885 is a wasteful number, since it uses less digits than its factorization.

639403885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 649343.

The product of its (nonzero) digits is 622080, while the sum is 46.

The square root of 639403885 is about 25286.4367794278. The cubic root of 639403885 is about 861.5062323078.

The spelling of 639403885 in words is "six hundred thirty-nine million, four hundred three thousand, eight hundred eighty-five".