639889830 has 24 divisors (see below), whose sum is σ = 1663713792. Its totient is φ = 170637264.

The previous prime is 639889801. The next prime is 639889883. The reversal of 639889830 is 38988936.

639889830 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3554854 + ... + 3555033.

It is an arithmetic number, because the mean of its divisors is an integer number (69321408).

Almost surely, 2^639889830 is an apocalyptic number.

639889830 is an abundant number, since it is smaller than the sum of its proper divisors (1023823962).

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

639889830 is a wasteful number, since it uses less digits than its factorization.

639889830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7109900 (or 7109897 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 54.

The square root of 639889830 is about 25296.0437618217. The cubic root of 639889830 is about 861.7244244106.

The spelling of 639889830 in words is "six hundred thirty-nine million, eight hundred eighty-nine thousand, eight hundred thirty".