638811 has 6 divisors (see below), whose sum is σ = 922740. Its totient is φ = 425868.

The previous prime is 638801. The next prime is 638819. The reversal of 638811 is 118836.

It is not a de Polignac number, because 638811 - 2¹⁰ = 637787 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638819) 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, 35481 + ... + 35498.

It is an arithmetic number, because the mean of its divisors is an integer number (153790).

2⁶³⁸⁸¹¹ is an apocalyptic number.

638811 is a deficient number, since it is larger than the sum of its proper divisors (283929).

638811 is a wasteful number, since it uses less digits than its factorization.

638811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70985 (or 70982 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 638811 is about 799.2565295323. The cubic root of 638811 is about 86.1239873758.

The spelling of 638811 in words is "six hundred thirty-eight thousand, eight hundred eleven".