638220 has 48 divisors (see below), whose sum is σ = 1951488. Its totient is φ = 154560.

The previous prime is 638201. The next prime is 638233. The reversal of 638220 is 22836.

638220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 177 + ... + 1143.

It is an arithmetic number, because the mean of its divisors is an integer number (40656).

2⁶³⁸²²⁰ is an apocalyptic number.

638220 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 638220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (975744).

638220 is an abundant number, since it is smaller than the sum of its proper divisors (1313268).

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

638220 is a wasteful number, since it uses less digits than its factorization.

638220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 990 (or 988 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 638220 is about 798.8867253873. The cubic root of 638220 is about 86.0974197988.

It can be divided in two parts, 638 and 220, that added together give a palindrome (858).

The spelling of 638220 in words is "six hundred thirty-eight thousand, two hundred twenty".