638786880 has 168 divisors, whose sum is σ = 2207571912. Its totient is φ = 169537536.

The previous prime is 638786879. The next prime is 638786893. The reversal of 638786880 is 88687836.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 238146624 + 400640256 = 15432^2 + 20016^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 843462 + ... + 844218.

It is an arithmetic number, because the mean of its divisors is an integer number (13140309).

Almost surely, 2^638786880 is an apocalyptic number.

638786880 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 638786880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1103785956).

638786880 is an abundant number, since it is smaller than the sum of its proper divisors (1568785032).

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

638786880 is a wasteful number, since it uses less digits than its factorization.

638786880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1073 (or 1060 counting only the distinct ones).

The product of its (nonzero) digits is 3096576, while the sum is 54.

The square root of 638786880 is about 25274.2335195353. The cubic root of 638786880 is about 861.2290341577.

The spelling of 638786880 in words is "six hundred thirty-eight million, seven hundred eighty-six thousand, eight hundred eighty".