638552819025 has 243 divisors, whose sum is σ = 1309833441553. Its totient is φ = 297135484800.

The previous prime is 638552818999. The next prime is 638552819029. The reversal of 638552819025 is 520918255836.

It is a happy number.

The square root of 638552819025 is 799095.

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

638552819025 is a `hidden beast` number, since 6 + 3 + 8 + 5 + 528 + 1 + 90 + 25 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 8777253969 + 629775565056 = 93687^2 + 793584^2 .

It is not a de Polignac number, because 638552819025 - 2⁹ = 638552818513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638552819029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 242 ways as a sum of consecutive naturals, for example, 3823669492 + ... + 3823669658.

Almost surely, 2^638552819025 is an apocalyptic number.

638552819025 is the 799095-th square number.

638552819025 is the 399548-th centered octagonal number.

It is an amenable number.

638552819025 is an abundant number, since it is smaller than the sum of its proper divisors (671280622528).

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

638552819025 is a wasteful number, since it uses less digits than its factorization.

638552819025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430 (or 215 counting only the distinct ones).

The product of its (nonzero) digits is 5184000, while the sum is 54.

The spelling of 638552819025 in words is "six hundred thirty-eight billion, five hundred fifty-two million, eight hundred nineteen thousand, twenty-five".