638165 has 16 divisors (see below), whose sum is σ = 858816. Its totient is φ = 451200.

The previous prime is 638161. The next prime is 638171. The reversal of 638165 is 561836.

It is not a de Polignac number, because 638165 - 2² = 638161 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 not an unprimeable number, because it can be changed into a prime (638161) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2114 + ... + 2396.

It is an arithmetic number, because the mean of its divisors is an integer number (53676).

2⁶³⁸¹⁶⁵ is an apocalyptic number.

It is an amenable number.

638165 is a deficient number, since it is larger than the sum of its proper divisors (220651).

638165 is a wasteful number, since it uses less digits than its factorization.

638165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340.

The product of its digits is 4320, while the sum is 29.

The square root of 638165 is about 798.8523017429. The cubic root of 638165 is about 86.0949465168.

It can be divided in two parts, 6381 and 65, that added together give a palindrome (6446).

The spelling of 638165 in words is "six hundred thirty-eight thousand, one hundred sixty-five".