638816255 has 16 divisors (see below), whose sum is σ = 955736064. Its totient is φ = 398222880.

The previous prime is 638816239. The next prime is 638816291. The reversal of 638816255 is 552618836.

638816255 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 638816255 - 2⁴ = 638816239 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 829247 + ... + 830016.

It is an arithmetic number, because the mean of its divisors is an integer number (59733504).

Almost surely, 2^638816255 is an apocalyptic number.

638816255 is a deficient number, since it is larger than the sum of its proper divisors (316919809).

638816255 is a wasteful number, since it uses less digits than its factorization.

638816255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1659286.

The product of its digits is 345600, while the sum is 44.

The square root of 638816255 is about 25274.8146382916. The cubic root of 638816255 is about 861.2422353342.

The spelling of 638816255 in words is "six hundred thirty-eight million, eight hundred sixteen thousand, two hundred fifty-five".