638764 has 18 divisors (see below), whose sum is σ = 1300740. Its totient is φ = 273672.

The previous prime is 638719. The next prime is 638767. The reversal of 638764 is 467836.

It is not an unprimeable number, because it can be changed into a prime (638767) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1434 + ... + 1825.

2⁶³⁸⁷⁶⁴ is an apocalyptic number.

It is an amenable number.

638764 is an abundant number, since it is smaller than the sum of its proper divisors (661976).

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

638764 is a wasteful number, since it uses less digits than its factorization.

638764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3277 (or 3268 counting only the distinct ones).

The product of its digits is 24192, while the sum is 34.

The square root of 638764 is about 799.2271266668. The cubic root of 638764 is about 86.1218751565.

The spelling of 638764 in words is "six hundred thirty-eight thousand, seven hundred sixty-four".