638648 has 16 divisors (see below), whose sum is σ = 1211280. Its totient is φ = 315648.

The previous prime is 638633. The next prime is 638663. The reversal of 638648 is 846836.

It is an interprime number because it is at equal distance from previous prime (638633) and next prime (638663).

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

638648 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 in 3 ways as a sum of consecutive naturals, for example, 365 + ... + 1187.

It is an arithmetic number, because the mean of its divisors is an integer number (75705).

2⁶³⁸⁶⁴⁸ is an apocalyptic number.

It is an amenable number.

638648 is a deficient number, since it is larger than the sum of its proper divisors (572632).

638648 is a wasteful number, since it uses less digits than its factorization.

638648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 926 (or 922 counting only the distinct ones).

The product of its digits is 27648, while the sum is 35.

The square root of 638648 is about 799.1545532624. The cubic root of 638648 is about 86.1166615762.

The spelling of 638648 in words is "six hundred thirty-eight thousand, six hundred forty-eight".