638899 has 4 divisors (see below), whose sum is σ = 660960. Its totient is φ = 616840.

The previous prime is 638893. The next prime is 638923. The reversal of 638899 is 998836.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 638899 - 2¹¹ = 636851 is a prime.

It is a d-powerful number, because it can be written as 6⁶ + 3¹² + 8³ + 8³ + 9³ + 9⁵ .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638893) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10987 + ... + 11044.

It is an arithmetic number, because the mean of its divisors is an integer number (165240).

2⁶³⁸⁸⁹⁹ is an apocalyptic number.

638899 is a deficient number, since it is larger than the sum of its proper divisors (22061).

638899 is a wasteful number, since it uses less digits than its factorization.

638899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22060.

The product of its digits is 93312, while the sum is 43.

The square root of 638899 is about 799.3115787977. The cubic root of 638899 is about 86.1279418907.

The spelling of 638899 in words is "six hundred thirty-eight thousand, eight hundred ninety-nine".