639788 has 12 divisors (see below), whose sum is σ = 1125432. Its totient is φ = 318240.

The previous prime is 639757. The next prime is 639833. The reversal of 639788 is 887936.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 639788.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 968 + ... + 1488.

It is an arithmetic number, because the mean of its divisors is an integer number (93786).

2⁶³⁹⁷⁸⁸ is an apocalyptic number.

It is an amenable number.

639788 is a deficient number, since it is larger than the sum of its proper divisors (485644).

639788 is a wasteful number, since it uses less digits than its factorization.

639788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 832 (or 830 counting only the distinct ones).

The product of its digits is 72576, while the sum is 41.

The square root of 639788 is about 799.8674890255. The cubic root of 639788 is about 86.1678711305.

The spelling of 639788 in words is "six hundred thirty-nine thousand, seven hundred eighty-eight".