638285478 has 16 divisors (see below), whose sum is σ = 1278790320. Its totient is φ = 212391936.

The previous prime is 638285471. The next prime is 638285497. The reversal of 638285478 is 874582836.

It is a happy number.

638285478 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 638285478.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638285471) 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, 88723 + ... + 95646.

It is an arithmetic number, because the mean of its divisors is an integer number (79924395).

Almost surely, 2^638285478 is an apocalyptic number.

638285478 is an abundant number, since it is smaller than the sum of its proper divisors (640504842).

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

638285478 is a wasteful number, since it uses less digits than its factorization.

638285478 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184951.

The product of its digits is 2580480, while the sum is 51.

The square root of 638285478 is about 25264.3123397412. The cubic root of 638285478 is about 861.0036407826.

The spelling of 638285478 in words is "six hundred thirty-eight million, two hundred eighty-five thousand, four hundred seventy-eight".