518443638138 has 24 divisors (see below), whose sum is σ = 1124091832500. Its totient is φ = 172691887104.

The previous prime is 518443638109. The next prime is 518443638151. The reversal of 518443638138 is 831836344815.

518443638138 is a `hidden beast` number, since 5 + 1 + 8 + 443 + 63 + 8 + 138 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 503820298809 + 14623339329 = 709803^2 + 120927^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10195513 + ... + 10246236.

Almost surely, 2^518443638138 is an apocalyptic number.

518443638138 is an abundant number, since it is smaller than the sum of its proper divisors (605648194362).

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

518443638138 is a wasteful number, since it uses less digits than its factorization.

518443638138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20443166 (or 20443163 counting only the distinct ones).

The product of its digits is 6635520, while the sum is 54.

The spelling of 518443638138 in words is "five hundred eighteen billion, four hundred forty-three million, six hundred thirty-eight thousand, one hundred thirty-eight".