639664070 has 32 divisors (see below), whose sum is σ = 1213332480. Its totient is φ = 242131680.

The previous prime is 639664057. The next prime is 639664111. The reversal of 639664070 is 70466936.

It is a happy number.

639664070 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 297419 + ... + 299561.

It is an arithmetic number, because the mean of its divisors is an integer number (37916640).

Almost surely, 2^639664070 is an apocalyptic number.

639664070 is a deficient number, since it is larger than the sum of its proper divisors (573668410).

639664070 is a wasteful number, since it uses less digits than its factorization.

639664070 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3740.

The product of its (nonzero) digits is 163296, while the sum is 41.

The square root of 639664070 is about 25291.5810102888. The cubic root of 639664070 is about 861.6230706148.

The spelling of 639664070 in words is "six hundred thirty-nine million, six hundred sixty-four thousand, seventy".