638105 has 8 divisors (see below), whose sum is σ = 824712. Its totient is φ = 471168.

The previous prime is 638081. The next prime is 638117. The reversal of 638105 is 501836.

It can be written as a sum of positive squares in 4 ways, for example, as 135424 + 502681 = 368^2 + 709^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 638105 - 2¹⁴ = 621721 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4844 + ... + 4973.

It is an arithmetic number, because the mean of its divisors is an integer number (103089).

2⁶³⁸¹⁰⁵ is an apocalyptic number.

638105 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

638105 is a deficient number, since it is larger than the sum of its proper divisors (186607).

638105 is a wasteful number, since it uses less digits than its factorization.

638105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9835.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 638105 is about 798.8147469846. The cubic root of 638105 is about 86.0922482289.

The spelling of 638105 in words is "six hundred thirty-eight thousand, one hundred five".