639528406 has 16 divisors (see below), whose sum is σ = 1108060560. Its totient is φ = 273594880.

The previous prime is 639528403. The next prime is 639528433. The reversal of 639528406 is 604825936.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639528403) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 854611 + ... + 855358.

It is an arithmetic number, because the mean of its divisors is an integer number (69253785).

Almost surely, 2^639528406 is an apocalyptic number.

639528406 is a deficient number, since it is larger than the sum of its proper divisors (468532154).

639528406 is a wasteful number, since it uses less digits than its factorization.

639528406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1709999.

The product of its (nonzero) digits is 311040, while the sum is 43.

The square root of 639528406 is about 25288.8988688713. The cubic root of 639528406 is about 861.5621534853.

The spelling of 639528406 in words is "six hundred thirty-nine million, five hundred twenty-eight thousand, four hundred six".