638485 has 8 divisors (see below), whose sum is σ = 770616. Its totient is φ = 507840.

The previous prime is 638467. The next prime is 638489. The reversal of 638485 is 584836.

It can be written as a sum of positive squares in 4 ways, for example, as 1681 + 636804 = 41^2 + 798^2 .

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

It is not a de Polignac number, because 638485 - 2⁵ = 638453 is a prime.

It is a Duffinian number.

638485 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 638485.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638489) by changing a digit.

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, 1155 + ... + 1615.

It is an arithmetic number, because the mean of its divisors is an integer number (96327).

2⁶³⁸⁴⁸⁵ is an apocalyptic number.

It is an amenable number.

638485 is a deficient number, since it is larger than the sum of its proper divisors (132131).

638485 is a wasteful number, since it uses less digits than its factorization.

638485 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 743.

The product of its digits is 23040, while the sum is 34.

The square root of 638485 is about 799.0525639781. The cubic root of 638485 is about 86.1093345300.

The spelling of 638485 in words is "six hundred thirty-eight thousand, four hundred eighty-five".