639085436 has 48 divisors (see below), whose sum is σ = 1257379200. Its totient is φ = 281709120.

The previous prime is 639085411. The next prime is 639085457. The reversal of 639085436 is 634580936.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 280775 + ... + 283041.

It is an arithmetic number, because the mean of its divisors is an integer number (26195400).

Almost surely, 2^639085436 is an apocalyptic number.

It is an amenable number.

639085436 is a deficient number, since it is larger than the sum of its proper divisors (618293764).

639085436 is a wasteful number, since it uses less digits than its factorization.

639085436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2474 (or 2472 counting only the distinct ones).

The product of its (nonzero) digits is 466560, while the sum is 44.

The square root of 639085436 is about 25280.1391610094. The cubic root of 639085436 is about 861.3631869065.

The spelling of 639085436 in words is "six hundred thirty-nine million, eighty-five thousand, four hundred thirty-six".