638120808 has 64 divisors (see below), whose sum is σ = 1908916800. Its totient is φ = 196344000.

The previous prime is 638120803. The next prime is 638120827. The reversal of 638120808 is 808021836.

638120808 is a `hidden beast` number, since 638 + 12 + 0 + 8 + 0 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (638120803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 110818 + ... + 116433.

It is an arithmetic number, because the mean of its divisors is an integer number (29826825).

Almost surely, 2^638120808 is an apocalyptic number.

It is an amenable number.

638120808 is an abundant number, since it is smaller than the sum of its proper divisors (1270795992).

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

638120808 is a wasteful number, since it uses less digits than its factorization.

638120808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227279 (or 227269 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 638120808 is about 25261.0531846952. The cubic root of 638120808 is about 860.9295915424.

The spelling of 638120808 in words is "six hundred thirty-eight million, one hundred twenty thousand, eight hundred eight".