639105 has 16 divisors (see below), whose sum is σ = 1033344. Its totient is φ = 337280.

The previous prime is 639091. The next prime is 639137. The reversal of 639105 is 501936.

It is not a de Polignac number, because 639105 - 2⁷ = 638977 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

639105 is a lucky number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1900 + ... + 2210.

It is an arithmetic number, because the mean of its divisors is an integer number (64584).

2⁶³⁹¹⁰⁵ is an apocalyptic number.

It is an amenable number.

639105 is a deficient number, since it is larger than the sum of its proper divisors (394239).

639105 is a wasteful number, since it uses less digits than its factorization.

639105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 456.

The product of its (nonzero) digits is 810, while the sum is 24.

The square root of 639105 is about 799.4404293004. The cubic root of 639105 is about 86.1371976309.

The spelling of 639105 in words is "six hundred thirty-nine thousand, one hundred five".