638676 has 36 divisors (see below), whose sum is σ = 1639092. Its totient is φ = 209664.

The previous prime is 638669. The next prime is 638689. The reversal of 638676 is 676836.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 76176 + 562500 = 276^2 + 750^2 .

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 self number, because there is not a number n which added to its sum of digits gives 638676.

It is a congruent number.

It is an unprimeable number.

638676 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, 3990 + ... + 4146.

2⁶³⁸⁶⁷⁶ is an apocalyptic number.

It is an amenable number.

638676 is an abundant number, since it is smaller than the sum of its proper divisors (1000416).

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

638676 is a wasteful number, since it uses less digits than its factorization.

638676 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280 (or 275 counting only the distinct ones).

The product of its digits is 36288, while the sum is 36.

The square root of 638676 is about 799.1720715841. The cubic root of 638676 is about 86.1179200844.

The spelling of 638676 in words is "six hundred thirty-eight thousand, six hundred seventy-six".