638834238 has 24 divisors (see below), whose sum is σ = 1581875568. Its totient is φ = 182524032.

The previous prime is 638834233. The next prime is 638834239. The reversal of 638834238 is 832438836.

638834238 is a `hidden beast` number, since 6 + 388 + 34 + 238 = 666.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 638834193 and 638834202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638834233) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2534931 + ... + 2535182.

It is an arithmetic number, because the mean of its divisors is an integer number (65911482).

Almost surely, 2^638834238 is an apocalyptic number.

638834238 is an abundant number, since it is smaller than the sum of its proper divisors (943041330).

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

638834238 is a wasteful number, since it uses less digits than its factorization.

638834238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5070128 (or 5070125 counting only the distinct ones).

The product of its digits is 663552, while the sum is 45.

The square root of 638834238 is about 25275.1703851824. The cubic root of 638834238 is about 861.2503167263.

It can be divided in two parts, 63883 and 4238, that added together give a square (68121 = 261²).

The spelling of 638834238 in words is "six hundred thirty-eight million, eight hundred thirty-four thousand, two hundred thirty-eight".