638820330863 has 16 divisors (see below), whose sum is σ = 790002326400. Its totient is φ = 507858634080.

The previous prime is 638820330773. The next prime is 638820330961. The reversal of 638820330863 is 368033028836.

It is a cyclic number.

It is not a de Polignac number, because 638820330863 - 2²⁰ = 638819282287 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638820330263) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 117557153 + ... + 117562586.

It is an arithmetic number, because the mean of its divisors is an integer number (49375145400).

Almost surely, 2^638820330863 is an apocalyptic number.

638820330863 is a deficient number, since it is larger than the sum of its proper divisors (151181995537).

638820330863 is a wasteful number, since it uses less digits than its factorization.

638820330863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235119782.

The product of its (nonzero) digits is 2985984, while the sum is 50.

The spelling of 638820330863 in words is "six hundred thirty-eight billion, eight hundred twenty million, three hundred thirty thousand, eight hundred sixty-three".