638403428238 has 8 divisors (see below), whose sum is σ = 1276806856488. Its totient is φ = 212801142744.

The previous prime is 638403428237. The next prime is 638403428249. The reversal of 638403428238 is 832824304836.

It is a sphenic number, since it is the product of 3 distinct primes.

638403428238 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638403428237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53200285681 + ... + 53200285692.

It is an arithmetic number, because the mean of its divisors is an integer number (159600857061).

Almost surely, 2^638403428238 is an apocalyptic number.

638403428238 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

638403428238 is a wasteful number, since it uses less digits than its factorization.

638403428238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106400571378.

The product of its (nonzero) digits is 5308416, while the sum is 51.

The spelling of 638403428238 in words is "six hundred thirty-eight billion, four hundred three million, four hundred twenty-eight thousand, two hundred thirty-eight".