638810220 has 24 divisors (see below), whose sum is σ = 1788668784. Its totient is φ = 170349376.

The previous prime is 638810213. The next prime is 638810297. The reversal of 638810220 is 22018836.

638810220 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5323359 + ... + 5323478.

It is an arithmetic number, because the mean of its divisors is an integer number (74527866).

Almost surely, 2^638810220 is an apocalyptic number.

638810220 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

638810220 is an abundant number, since it is smaller than the sum of its proper divisors (1149858564).

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

638810220 is a wasteful number, since it uses less digits than its factorization.

638810220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10646849 (or 10646847 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 638810220 is about 25274.6952503883. The cubic root of 638810220 is about 861.2395232277.

The spelling of 638810220 in words is "six hundred thirty-eight million, eight hundred ten thousand, two hundred twenty".