639506 has 16 divisors (see below), whose sum is σ = 1161216. Its totient is φ = 257856.

The previous prime is 639493. The next prime is 639511. The reversal of 639506 is 605936.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1106 + ... + 1581.

It is an arithmetic number, because the mean of its divisors is an integer number (72576).

2⁶³⁹⁵⁰⁶ is an apocalyptic number.

639506 is a deficient number, since it is larger than the sum of its proper divisors (521710).

639506 is a wasteful number, since it uses less digits than its factorization.

639506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2713.

The product of its (nonzero) digits is 4860, while the sum is 29.

The square root of 639506 is about 799.6911903979. The cubic root of 639506 is about 86.1552091703.

The spelling of 639506 in words is "six hundred thirty-nine thousand, five hundred six".