638129368900 has 243 divisors, whose sum is σ = 1523816291781. Its totient is φ = 231903544320.

The previous prime is 638129368897. The next prime is 638129368931. The reversal of 638129368900 is 9863921836.

The square root of 638129368900 is 798830.

It is a perfect power (a square), and thus also a powerful number.

638129368900 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 13 ways, for example, as 19729573444 + 618399795456 = 140462^2 + 786384^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 5024640637 + ... + 5024640763.

Almost surely, 2^638129368900 is an apocalyptic number.

638129368900 is the 798830-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638129368900

638129368900 is an abundant number, since it is smaller than the sum of its proper divisors (885686922881).

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

638129368900 is a wasteful number, since it uses less digits than its factorization.

638129368900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376 (or 188 counting only the distinct ones).

The product of its (nonzero) digits is 3359232, while the sum is 55.

The spelling of 638129368900 in words is "six hundred thirty-eight billion, one hundred twenty-nine million, three hundred sixty-eight thousand, nine hundred".