638280 has 80 divisors (see below), whose sum is σ = 2156220. Its totient is φ = 169344.

The previous prime is 638269. The next prime is 638303. The reversal of 638280 is 82836.

638280 is a `hidden beast` number, since 638 + 28 + 0 = 666.

638280 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 599076 + 39204 = 774^2 + 198^2 .

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3142 + ... + 3338.

2⁶³⁸²⁸⁰ is an apocalyptic number.

638280 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1078110).

638280 is an abundant number, since it is smaller than the sum of its proper divisors (1517940).

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

638280 is a wasteful number, since it uses less digits than its factorization.

638280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220 (or 207 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 638280 is about 798.9242767622. The cubic root of 638280 is about 86.1001177626.

The spelling of 638280 in words is "six hundred thirty-eight thousand, two hundred eighty".