638768 has 40 divisors (see below), whose sum is σ = 1385328. Its totient is φ = 283392.

The previous prime is 638767. The next prime is 638801. The reversal of 638768 is 867836.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 638768.

It is not an unprimeable number, because it can be changed into a prime (638767) 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, 7655 + ... + 7737.

2⁶³⁸⁷⁶⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (692664).

638768 is an abundant number, since it is smaller than the sum of its proper divisors (746560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638768 is a wasteful number, since it uses less digits than its factorization.

638768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141 (or 135 counting only the distinct ones).

The product of its digits is 48384, while the sum is 38.

The square root of 638768 is about 799.2296290804. The cubic root of 638768 is about 86.1220549239.

It can be divided in two parts, 638 and 768, that multiplied together give a palindrome (489984).

The spelling of 638768 in words is "six hundred thirty-eight thousand, seven hundred sixty-eight".