638543158 has 16 divisors (see below), whose sum is σ = 1090319616. Its totient is φ = 277627240.

The previous prime is 638543131. The next prime is 638543159. The reversal of 638543158 is 851345836.

638543158 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 3×638543158³ (a number of 27 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638543159) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 630466 + ... + 631477.

It is an arithmetic number, because the mean of its divisors is an integer number (68144976).

Almost surely, 2^638543158 is an apocalyptic number.

638543158 is a deficient number, since it is larger than the sum of its proper divisors (451776458).

638543158 is a wasteful number, since it uses less digits than its factorization.

638543158 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1261979.

The product of its digits is 345600, while the sum is 43.

The square root of 638543158 is about 25269.4115087788. The cubic root of 638543158 is about 861.1194894515.

The spelling of 638543158 in words is "six hundred thirty-eight million, five hundred forty-three thousand, one hundred fifty-eight".