638017081 has 27 divisors (see below), whose sum is σ = 726353901. Its totient is φ = 560143584.

The previous prime is 638017067. The next prime is 638017141. The reversal of 638017081 is 180710836.

The square root of 638017081 is 25259.

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

638017081 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 4 ways, for example, as 81812025 + 556205056 = 9045^2 + 23584^2 .

It is not a de Polignac number, because 638017081 - 2¹⁷ = 637886009 is a prime.

It is a super-2 number, since 2×638017081² = 814131591295521122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (638017001) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 9522610 + ... + 9522676.

Almost surely, 2^638017081 is an apocalyptic number.

638017081 is the 25259-th square number.

638017081 is the 12630-th centered octagonal number.

It is an amenable number.

638017081 is a deficient number, since it is larger than the sum of its proper divisors (88336820).

638017081 is an equidigital number, since it uses as much as digits as its factorization.

638017081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 218 (or 109 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 34.

The cubic root of 638017081 is about 860.8829407715.

The spelling of 638017081 in words is "six hundred thirty-eight million, seventeen thousand, eighty-one".