638217 has 6 divisors (see below), whose sum is σ = 921882. Its totient is φ = 425472.

The previous prime is 638201. The next prime is 638233. The reversal of 638217 is 712836.

638217 is a `hidden beast` number, since 638 + 21 + 7 = 666.

638217 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (638201) and next prime (638233).

It can be written as a sum of positive squares in only one way, i.e., 553536 + 84681 = 744^2 + 291^2 .

It is not a de Polignac number, because 638217 - 2⁴ = 638201 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638117) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 35448 + ... + 35465.

It is an arithmetic number, because the mean of its divisors is an integer number (153647).

2⁶³⁸²¹⁷ is an apocalyptic number.

It is an amenable number.

638217 is a deficient number, since it is larger than the sum of its proper divisors (283665).

638217 is a wasteful number, since it uses less digits than its factorization.

638217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70919 (or 70916 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 638217 is about 798.8848477722. The cubic root of 638217 is about 86.0972848962.

The spelling of 638217 in words is "six hundred thirty-eight thousand, two hundred seventeen".