638362377538 has 8 divisors (see below), whose sum is σ = 957574479420. Its totient is φ = 319170884400.

The previous prime is 638362377449. The next prime is 638362377539. The reversal of 638362377538 is 835773263836.

It can be written as a sum of positive squares in 2 ways, for example, as 570951005769 + 67411371769 = 755613^2 + 259637^2 .

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

It is not an unprimeable number, because it can be changed into a prime (638362377539) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5074513 + ... + 5198788.

Almost surely, 2^638362377538 is an apocalyptic number.

638362377538 is a deficient number, since it is larger than the sum of its proper divisors (319212101882).

638362377538 is a wasteful number, since it uses less digits than its factorization.

638362377538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10304372.

The product of its digits is 91445760, while the sum is 61.

The spelling of 638362377538 in words is "six hundred thirty-eight billion, three hundred sixty-two million, three hundred seventy-seven thousand, five hundred thirty-eight".