639790 has 16 divisors (see below), whose sum is σ = 1162512. Its totient is φ = 253504.

The previous prime is 639757. The next prime is 639833. The reversal of 639790 is 97936.

639790 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a d-powerful number, because it can be written as 6⁶ + 3⁵ + 7⁴ + 9⁵ + 9⁶ + 0 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1137 + ... + 1603.

It is an arithmetic number, because the mean of its divisors is an integer number (72657).

2⁶³⁹⁷⁹⁰ is an apocalyptic number.

639790 is a deficient number, since it is larger than the sum of its proper divisors (522722).

639790 is a wasteful number, since it uses less digits than its factorization.

639790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 611.

The product of its (nonzero) digits is 10206, while the sum is 34.

The square root of 639790 is about 799.8687392316. The cubic root of 639790 is about 86.1679609184.

The spelling of 639790 in words is "six hundred thirty-nine thousand, seven hundred ninety".