638748 has 36 divisors (see below), whose sum is σ = 1762488. Its totient is φ = 193440.

The previous prime is 638719. The next prime is 638767. The reversal of 638748 is 847836.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a plaindrome in base 14.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 638748.

It is an unprimeable number.

638748 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 11 ways as a sum of consecutive naturals, for example, 411 + ... + 1202.

It is an arithmetic number, because the mean of its divisors is an integer number (48958).

2⁶³⁸⁷⁴⁸ is an apocalyptic number.

It is an amenable number.

638748 is an abundant number, since it is smaller than the sum of its proper divisors (1123740).

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

638748 is a wasteful number, since it uses less digits than its factorization.

638748 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1634 (or 1629 counting only the distinct ones).

The product of its digits is 32256, while the sum is 36.

The square root of 638748 is about 799.2171169338. The cubic root of 638748 is about 86.1211560795.

The spelling of 638748 in words is "six hundred thirty-eight thousand, seven hundred forty-eight".