638216 has 8 divisors (see below), whose sum is σ = 1196670. Its totient is φ = 319104.

The previous prime is 638201. The next prime is 638233. The reversal of 638216 is 612836.

It can be written as a sum of positive squares in only one way, i.e., 417316 + 220900 = 646^2 + 470^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

638216 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39881 + ... + 39896.

2⁶³⁸²¹⁶ is an apocalyptic number.

It is an amenable number.

638216 is a deficient number, since it is larger than the sum of its proper divisors (558454).

638216 is a wasteful number, since it uses less digits than its factorization.

638216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79783 (or 79779 counting only the distinct ones).

The product of its digits is 1728, while the sum is 26.

The square root of 638216 is about 798.8842218995. The cubic root of 638216 is about 86.0972399286.

The spelling of 638216 in words is "six hundred thirty-eight thousand, two hundred sixteen".