638928448900 has 243 divisors, whose sum is σ = 1705028837967. Its totient is φ = 207186336000.

The previous prime is 638928448861. The next prime is 638928448933. The reversal of 638928448900 is 9844829836.

The square root of 638928448900 is 799330.

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

It can be written as a sum of positive squares in 4 ways, for example, as 33980498244 + 604947950656 = 184338^2 + 777784^2 .

It is a super-2 number, since 2×638928448900² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 1063108600 + ... + 1063109200.

Almost surely, 2^638928448900 is an apocalyptic number.

638928448900 is the 799330-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638928448900

638928448900 is an abundant number, since it is smaller than the sum of its proper divisors (1066100389067).

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

638928448900 is a wasteful number, since it uses less digits than its factorization.

638928448900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1268 (or 634 counting only the distinct ones).

The product of its (nonzero) digits is 23887872, while the sum is 61.

The spelling of 638928448900 in words is "six hundred thirty-eight billion, nine hundred twenty-eight million, four hundred forty-eight thousand, nine hundred".