638968 has 32 divisors (see below), whose sum is σ = 1341360. Its totient is φ = 282880.

The previous prime is 638959. The next prime is 638971. The reversal of 638968 is 869836.

It is a self number, because there is not a number n which added to its sum of digits gives 638968.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4596 + ... + 4732.

2⁶³⁸⁹⁶⁸ 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 638968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (670680).

638968 is an abundant number, since it is smaller than the sum of its proper divisors (702392).

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

638968 is a wasteful number, since it uses less digits than its factorization.

638968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207 (or 203 counting only the distinct ones).

The product of its digits is 62208, while the sum is 40.

The square root of 638968 is about 799.3547397745. The cubic root of 638968 is about 86.1310423359.

The spelling of 638968 in words is "six hundred thirty-eight thousand, nine hundred sixty-eight".