638638782 has 16 divisors (see below), whose sum is σ = 1277932032. Its totient is φ = 212770520.

The previous prime is 638638757. The next prime is 638638799. The reversal of 638638782 is 287836836.

638638782 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×638638782³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14094 + ... + 38417.

It is an arithmetic number, because the mean of its divisors is an integer number (79870752).

Almost surely, 2^638638782 is an apocalyptic number.

638638782 is an abundant number, since it is smaller than the sum of its proper divisors (639293250).

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

638638782 is a wasteful number, since it uses less digits than its factorization.

638638782 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54543.

The product of its digits is 2322432, while the sum is 51.

The square root of 638638782 is about 25271.3035279148. The cubic root of 638638782 is about 861.1624724923.

The spelling of 638638782 in words is "six hundred thirty-eight million, six hundred thirty-eight thousand, seven hundred eighty-two".