639645606 has 32 divisors (see below), whose sum is σ = 1425062880. Its totient is φ = 212671008.

The previous prime is 639645593. The next prime is 639645641. The reversal of 639645606 is 606546936.

639645606 is a `hidden beast` number, since 6 + 39 + 6 + 4 + 5 + 606 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6520 + ... + 36356.

It is an arithmetic number, because the mean of its divisors is an integer number (44533215).

Almost surely, 2^639645606 is an apocalyptic number.

639645606 is an abundant number, since it is smaller than the sum of its proper divisors (785417274).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

639645606 is a wasteful number, since it uses less digits than its factorization.

639645606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30245 (or 30239 counting only the distinct ones).

The product of its (nonzero) digits is 699840, while the sum is 45.

The square root of 639645606 is about 25291.2159850016. The cubic root of 639645606 is about 861.6147802416.

The spelling of 639645606 in words is "six hundred thirty-nine million, six hundred forty-five thousand, six hundred six".